¹ North Sea Continental Shelf Cases (Ger./Den.; Ger./Neth.), Judgment, 1969 ICJ Rep. 3, para. 73 (Feb. 20) [hereinafter North Sea Continental Shelf Judgment].

² Tladi, Dire, Progressive Development and Codification of International Law: The Work of the International Law Commission During Its Sixty-Sixth Session, 38 S. Afr. Y.B. of Int'l L. 124, 130 (2013)Google Scholar.

³ This article will refer to both the “doctrine of specially-affected states” and the “specially-affected states requirement.” The latter expression is more specific, referring specifically to North Sea Continental Shelf’s insistence that state practice cannot be widespread and representative unless it includes the practice of specially-affected states. The former expression refers more generally to the meaning and importance of the specially-affected states requirement.

⁴ Gennady Danilenko, Law-Making in the International Community 96 (1993).

⁵ Int'l Law Comm'n, Rep. on the Work of Its Sixty-Sixth Session, UN Doc. A/69/10, at 223 (2014) (Draft Conclusion 9) [hereinafter Second ILC Report on Custom].

⁶ Id., para. 168.

⁷ Int'l Law Comm'n, Rep. on the Work of Its Sixty-Eighth Session, UN Doc. A/71/10, at 95 (2016) [hereinafter Fourth ILC Report on Custom]. Although it does not use the term, the commentary is referring to the concept of specially-affected states. See Tladi, supra note 2, at 131 (“[T]he Special Rapporteur decided not to pursue the provision in the Drafting Committee. He decided that he would, instead, include references to specially affected states in the commentaries.”).

⁸ Email from Sir Michael Wood, ILC Special Rapporteur on Identification of Customary International Law (Feb. 13, 2018) (on file with author).

⁹ U.S. Dep't of State, Office of the Legal Advisor, Remarks of Stephen Townley, Counselor for Legal Affairs for the U.S. Mission to the UN, to the 69th General Assembly Sixth Committee, 2014 Dig. U.S. Prac. Int'l L. 295, 296–97 (2014) (noting, in response to the deletion of specially-affected states from the ILC's Draft Conclusions, that the United States believes “the role of the practice of such States in the identification of customary international law should be recognized and addressed in the final product of this exercise, so as to reflect accurately international law”).

¹⁰ It is impossible to know, of course, to what extent the United States has thought through the implications of its public statements concerning the specially-affected states doctrine. If this article encourages U.S. officials to reconsider those implications, all the better.

¹¹ See, e.g., Galindo, George Rodrigo Bandeira & Yip, Cesar, Customary International Law and the Third World: Do Not Step on the Grass, 16 Chinese J. Int'l L. 1, 8 (2017)Google Scholar (“Effectively, scholars, courts and lawyers generally can more easily obtain documents proving the practice of western states than of the Third World.”); Akehurst, Michael, Custom as a Source of International Law, 47 Brit. Y.B. Int'l L. 1, 23 (1976)Google Scholar (“Of course some States exercise a greater influence on the development of customary law than other States, but that is because the practice of some States is more frequent or better publicized than the practice of other States, not because it is intrinsically more important than the practice of other States.”).

¹² Galindo & Yip, supra note 11, at 7–8 n. 31.

¹³ Cf. Hofmann, Rainer, Comment on Skordas, in United States Hegemony and the Foundations of International Law 348, 349 (Byers, Michael & Nolte, George eds., 2003)Google Scholar (“In the ‘old’ bipolar world, the United States would, when considering the issue of creating customary international law, not have been treated any differently from any other State—at least from a strictly legal point of view. Instead, it would have had to contribute to the creation of customary law by pursuing its own practice and persuading other members of the international community to follow that practice.”).

¹⁴ North Sea Continental Shelf Cases (Ger./Den.; Ger./Neth.), Common Rejoinder Submitted by the Governments of the Kingdom of Denmark and the Kingdom of the Netherlands, 1968 ICJ Plead. 479 (Aug. 30).

¹⁵ North Sea Continental Shelf Cases (Ger./Den.; Ger./Neth.), Reply Submitted by the Government of the Federal Republic of Germany, 1968 ICJ Plead. 407–08 (May 31).

¹⁶ North Sea Continental Shelf Cases (Ger./Den.; Ger./Neth.), Memorial Submitted by the Government of the Federal Republic of Germany, 1967 ICJ Plead. 57 (Aug. 21).

¹⁷ North Sea Continental Shelf, Judgment, supra note 1, at 42, para. 73.

¹⁸ Id. at 43, para. 74.

¹⁹ Id. at 25, para. 26.

²⁰ Id. at 43, para. 73.

²¹ Afghanistan, Belarus, Bolivia, Malawi, Nepal, Switzerland, and Uganda. See Convention on the Continental Shelf, Ratifying Parties, at https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXI-4&chapter=21&clang=_en.

²² The 104 number comes from Judge Lachs, who noted in his dissent that “[t]wenty-six of the total number of States in existence [130] are … land-locked and cannot be considered as having a special and immediate interest in speedy accession to the Convention.” North Sea Continental Shelf Judgment, supra note 1, at 227 (Dissenting Opinion of Judge Lachs).

²³ Id. at 25, para. 28.

²⁴ Id. at 44, para. 75 (noting that the delimitations cited by Denmark and the Netherlands “constituted [no] more than a very small proportion of those potentially calling for delimitation in the world as a whole”).

²⁵ See, e.g., Fisheries Jurisdiction (UK/Ice.; Ger./Ice.), Separate Opinion of Judge De Castro, 1974 ICJ Rep. 90 (July 25) (“For a new rule of international law to be formed, the practice of States, including those whose interests are specially affected, must have been substantially or practically uniform.”).

²⁶ Military and Paramilitary Activities in and Against Nicaragua (Nicar./U.S.), Merits, Judgment, 1986 ICJ Rep. 108–09, para. 207 (June 27).

²⁷ Jurisdictional Immunities of the State (Ger./It.: Greece Intervening), Judgment, 2012 ICJ Rep. 122, para. 55 (Feb. 3).

²⁸ Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 ICJ Rep. 226 (July 8) [hereinafter Nuclear Weapons Advisory Opinion].

²⁹ See Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, Letter Dated 20 June 1995 from the Acting Legal Adviser to the Department of State, Together with Written Statement of the Government of the United States of America, 1995 ICJ Plead. 8–9 (June 20) [hereinafter U.S. Letter]; id., Verbatim Record, Statement of the United Kingdom, CR 95/34 (Nov. 15, 1995) [hereinafter UK Statement].

³⁰ Nuclear Weapons Advisory Opinion, supra note 28, at 255, paras. 71–73.

³¹ GA Res. 1653(XVI), UN GAOR, 16th Sess., Supp. No. 17, UN Doc. A/RES/1653(XVI) (1961). The abolitionist side also cited the “consistent practice of non-utilization of nuclear weapons by States since 1945” as evidence in favor of a customary prohibition of their use. Nuclear Weapons Advisory Opinion, supra note 28, at 252. The Court ignored that argument.

³² Nuclear Weapons Advisory Opinion, supra note 28, at 255, para. 71.

³³ See https://research.un.org/en/docs/ga/quick/regular/16.

³⁴ The United States, the United Kingdom, France, and the Soviet Union. See ICAN, Nuclear Weapons Timeline, at http://www.icanw.org/the-facts/the-nuclear-age.

³⁵ GA Res. 33/71B, UN GAOR, 33rd Sess., Supp. No. 45, UN Doc. A/RES/33/71B (1978).

³⁶ See http://research.un.org/en/docs/ga/quick/regular/33.

³⁷ China, Israel, and India had become nuclear powers since Resolution 1653 (XVI). See Nuclear Weapons Timeline, supra note 34.

³⁸ GA Res. 42/42A, UN GAOR, 42nd Sess., Supp. No. 49, UN Doc. A/RES/42/42A (1987).

³⁹ See http://research.un.org/en/docs/ga/quick/regular/42.

⁴⁰ GA Res. 50/71E, UN GAOR, 50th Sess., Supp. No. 49, UN Doc. A/RES/50/71E (1995).

⁴¹ See http://research.un.org/en/docs/ga/quick/regular/50.

⁴² Clark, Roger S., Treaty and Custom, in International Law, the International Court of Justice and Nuclear Weapons 171, 178 (de Chazournes, Laurence Boisson & Sands, Philippe eds., 1999)Google Scholar. It is worth noting that it is possible, though ultimately unconvincing, to read the judgment as obliquely referencing the doctrine of specially-affected states. First, the Court may not have credited the U.S. and UK position because it believed that all states were specially affected with regard to the use of nuclear weapons. That reading, however, is difficult to reconcile with Judge Weeramantry's and Judge Shahabuddeen's dissents, both of which specifically criticized the Court for not viewing all states as specially affected. See text accompanying note 168 infra. Second, it is also possible that the Court is alluding to the doctrine of specially-affected states in paragraph 73, the final paragraph in its discussion of custom, where it wrote that “[t]he emergence, as lex lata, of a customary rule specifically prohibiting the use of nuclear weapons as such is hampered by the continuing tensions between the nascent opinio juris on the one hand, and the still strong adherence to the practice of deterrence on the other.” Nuclear Weapons Advisory Opinion, supra note 28, at 255. This might be an acknowledgment of the U.S. and UK's insistence that they were specially affected, given that only nuclear powers can engage in deterrence. The precise meaning of paragraph 73, however, is impossible to divine with any certainty—and even if it does refer to the doctrine of specially-affected states, it does not answer any of the critical issues, such as who qualifies (only states that engage in deterrence?) and the importance of the status (does the opposition of the nuclear powers doom the customary rule no matter how many non-nuclear states oppose it?).

⁴³ Fisheries Jurisdiction, supra note 25, at 29, para. 67 (Judgment).

⁴⁴ See id. at 22–23, paras. 51–52.

⁴⁵ Id. at 23, para. 52.

⁴⁶ Id. at 29, paras. 66, 68.

⁴⁷ Id. Judge Petren explicitly relied on the doctrine of specially-affected states in his dissenting opinion, emphasizing that states distinctively affected by the expansion of exclusive fishing zones should be considered specially affected with regard to the customary rule. Although he did not believe that the number of coastal states claiming exclusive fishing zones beyond twelve miles was sufficient to satisfy the practice requirement, he specifically noted that “the States whose interests are threatened by these claims have constantly protested” them. Those protests, he insisted, would themselves have been sufficient to doom any rule permitting a more expansive exclusive fishing zone, because they meant that “another element which is necessary to the formation of a new rule of customary law is missing, namely its acceptance by those States whose interests it affects.” Id. at 161 (Dissenting Opinion of Judge Petren).

⁴⁸ Obligations Concerning Negotiations Relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (Marsh. Is./UK), Preliminary Objections, para. 44 (Int'l Ct. Just. Oct. 5, 2016).

⁴⁹ Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, Letter Dated 22 June 1995 from the Permanent Representative of the Marshall Islands to the United Nations, Together with the Written Statement of the Government of the Marshall Islands (Int'l Ct. Just. June 22, 1995), available at http://www.icj-cij.org/files/case-related/95/8720.pdf.

⁵⁰ Case of Readaptation of the Mavrommatis Jerusalem Concessions, Jurisdiction, 1927 PCIJ (ser. A), No. 11, at 18 (Oct. 10).

⁵¹ See, e.g., d'Aspremont, Jean, The Idea of “Rules” in the Sources of International Law, 84 Brit. Y.B. Int'l L. 103, 111 (2014)Google Scholar (noting that Article 38 “has been taken out of its institutional context and elevated into a sort of constitutional rule about the rules of international law”).

⁵² Nicholas Onuf, International Legal Theory: Essays and Engagements, 1966–2006, at 69 (2008).

⁵³ See d'Aspremont, supra note 51, at 111 (“[T]he ruleness of sources is supposed to be grounded in another and different layer of (meta-) rules. As a result, a problem of infinite regress arises. Such an infinite regress is inherent in a rule-based approach to sources: should the foundations of rules on sources be itself a rule, the question of the foundation of sources repeats itself ad infinitum.”).

⁵⁴ See text accompanying note 236 infra.

⁵⁵ Email from Sienho Yee, Special Rapporteur of the Asian-African Legal Consultative Organization (AALCO) Informal Expert Group (Feb. 10, 2018) (on file with author) (explaining that member states have voiced support for the AALCO Informal Expert Group's position that the doctrine is valid).

⁵⁶ As Petersen notes, determining the content of customary international law has always been one of the International Court of Justice's (ICJ) central preoccupations. Petersen, Niels, The International Court of Justice and the Judicial Politics of Identifying Customary International Law, 28 Eur. J. Int'l. L. 357, 385 (2017)CrossRefGoogle Scholar.

⁵⁷ Quoted in Gerry Simpson, Great Powers and Outlaw States: Unequal Sovereigns in the International Legal Order 27 (2004); see also id. at 26 (“It is a commonplace in international law that states are equal or, at least, that they possess something called sovereign equality. This form of equality is a foundational principle of the international legal order.”).

⁵⁸ Id. at 48.

⁵⁹ Id.

⁶⁰ A controversial possibility, to be sure. See note 232 infra.

⁶¹ See, e.g., Christian J. Tams & Antonios Tzanakopoulos, The Use of Force, in International Legal Positivism in a Post-Modern World 498, 510 (Jorg Kammerhofer & Jean d'Aspremont eds., 2014) (noting that the doctrine of specially-affected states “is best understood as qualifying the requirement of generality of practice”).

⁶² Nuclear Weapons Advisory Opinion, supra note 28, at 278 (Declaration of Judge Shi).

⁶³ Price, Richard, Emerging Customary Norms and Anti-Personnel Landmines, in The Politics of International Law 106, 120 (Reus-Smit, Christian ed., 2004)Google Scholar.

⁶⁴ Mark E. Villiger, Customary International Law and Treaties 15 (1985).

⁶⁵ Second ILC Report on Custom, supra note 5, at 228.

⁶⁶ Steven R. Ratner, The Thin Justice of International Law: A Moral Reckoning of the Law of Nations 209 (2015).

⁶⁷ Yee, Sienho, Report on the ILC Project on “Identification of Customary International Law,” 14 Chinese J. Int'l L. 375, 389 (2015)Google Scholar.

⁶⁸ See, e.g., Simpson, supra note 57, at 27 (noting that “the significance of sovereign equality is made explicit … in the 1970 Declaration on Friendly Relations”).

⁶⁹ See, e.g., Kohen, Marcelo, The Principle of Non-intervention 25 Years After the Nicaragua Judgment, 25 Leiden J. Int'l L. 157, 160 (2012)CrossRefGoogle Scholar. The international community's understanding of what kinds of activities directly affect other states has, of course, evolved over time. Id. But the underlying rationale has stayed the same.

⁷⁰ The idea of direct and indirect effect—including the possibility that some issues affect all states in a manner that rules out recognizing individual states as specially affected—is explored in more detail below. See text accompanying notes 184–191 infra.

⁷¹ U.S. Letter, supra note 29, at 9.

⁷² The United Kingdom took a slightly broader view, claiming that there was no consistency of practice supporting the existence of a customary rule prohibiting the use of nuclear weapons because “nuclear-weapon States and those States on whose territory such weapons are situated have, by word and deed, disavowed the existence of such a rule.” UK Statement, supra note 29, at 47. That expansion simply increased the number of specially-affected states opposed to the rule—which might well have been the UK's intention.

⁷³ Bellinger, John B. III & Haynes, William J. II, A U.S. Government Response to the International Committee of the Red Cross Study Customary International Humanitarian Law, 89 Int'l Rev. Red Cross 443, 445 n. 4 (2007)Google Scholar (internal citation omitted).

⁷⁴ Id. at 455.

⁷⁵ Department of Defense Law of War Manual, at v (2015). The Manual also says that, in the right circumstances, “occupying or occupied” states might qualify as specially affected. Id. The latter could obviously include weaker states, although the Manual does not explain how occupied states could have a “distinctive history” of occupation in a quantitative sense.

⁷⁶ Id. at 32.

⁷⁷ Id.

⁷⁸ This appears to be an even more uncompromising position than the one the United States took in the Nuclear Weapons case, in which it claimed that “customary law could not be created over the objection of the nuclear weapon States, which are the states whose interests are most specially affected.” U.S. Letter, supra note 29, at 9. That formulation left open the possibility that more than one specially-affected state has to oppose a rule to prevent it from passing into custom.

⁷⁹ See, e.g., Int'l Law Assoc., Statement of Principles Applicable to the Formation of General Customary International Law 14, Report of the Sixty-Ninth Conference (2000) (noting that state practice includes “policy statements,” “official manuals (e.g. on military law),” and “pleadings before international tribunals”) [hereinafter ILA Custom Report].

⁸⁰ See, e.g., Fourth ILC Report on Custom, supra note 7, at 77 (Draft Conclusion 10) (“Forms of evidence of acceptance as law (opinio juris) include, but are not limited to: public statements made on behalf of States; official publications; [and] government legal opinions.”)

⁸¹ See, e.g., id. at 18 (noting that inconsistent practice by a state reduces the weight that can be attached to individual instances of practice).

⁸² Townley Statement, supra note 9, at 296–97.

⁸³ The quotes in this section have been chosen because they articulate specifically legal claims. They do not simply make the (difficult to deny) legal-realist point that, as a matter of actual fact, powerful states tend to get their way internationally.

⁸⁴ Hans Kelsen, Pure Theory of Law 260–61 (Charles Eisenmann trans., 1962).

⁸⁵ Clagett, Brice M., Protection of Foreign Investment Under the Revised Restatement, 25 Va. J. Int'l L. 73, 89 (1984–1985)Google Scholar.

⁸⁶ See Harry H.G. Post, The Role of State Practice in the Formation of Customary International Humanitarian Law, in On the Foundations and Sources of International Law 129, 142 (Ige F. Dekker & Harry H.G. Post eds., 2003).

⁸⁷ Barnsby, Robert E., Yes, We Can: The Authority to Detain as Customary International Law, 202 Mil. L. Rev. 53, 75–76 (2009)Google Scholar.

⁸⁸ H.W.A. Thirlway, International Customary Law and Codification 72 (1972).

⁸⁹ MacLaren, Malcolm & Schwendimann, Felix, An Exercise in the Development of International Law: The New ICRC Study on Customary International Humanitarian Law, 6 German L.J. 1217, 1232 (2005)Google Scholar.

⁹⁰ Michael N. Schmitt & Liis Vihul, The Nature of International Law Cybernorms 25 (2014), available at https://ccdcoe.org/sites/default/files/multimedia/pdf/Tallinn%20Paper%20No%20%205%20Schmitt%20and%20Vihul.pdf.

⁹¹ Rudiger Wolfrum, Comment, in United States Hegemony, supra note 13, at 359–60.

⁹² Karen Hulme, Natural Environment, in Perspectives On The ICRC Study on Customary International Humanitarian Law 204, 233 (Elizabeth Wilmshurst & Susan Breau eds., 2007).

⁹³ American Law Institute, I Restatement of the Law (Third) Foreign Relations Law of the United States §102 cmt. i (1986).

⁹⁴ Clagett, supra note 85, at 90; cf. Thomas Buergenthal & Sean D. Murphy, Public International Law in a Nutshell 28 (4th ed. 2011) (claiming that it is “undisputed” that, to create custom, “the practice must be one that is accepted by the world's major powers and by states directly affected by it”).

⁹⁵ Malcolm N. Shaw, International Law 56 (7th ed. 2014) (emphasis added). Shaw's reference to a state's “special relationship” with a practice at least leaves open the possibility that a state does not have to engage in a practice to qualify as specially affected.

⁹⁶ Baxter, R. R., Treaties and Custom, 129 Collected Courses Hague Acad. Int'l L. 1, 66 (1979)Google Scholar. Reisman & Armstrong hint in the same direction, although not specifically in the context of specially-affected states, when they say that “doctrines of sovereign equality notwithstanding, the actions of a great power may be more generative of law than those of smaller states.” Reisman, W. Michael & Armstrong, Andrea, The Past and Future of the Claim of Preemptive Self-Defense, 100 AJIL 525, 526 (2006)Google Scholar.

⁹⁷ ICRC, I Customary International Humanitarian Law: Rules, at xliv–v (Jean-Marie Henckaerts & Louise Doswald-Beck eds., 2005) (“States whose population is in need of such aid or States which frequently provide such aid are to be considered ‘specially affected.’”)

⁹⁸ Porterfield, Matthew C., State Practice and the (Purported) Obligation Under Customary International Law to Provide Compensation for Regulatory Expropriations, 37 N.C. J. Int'l L. & Com. Reg. 160, 172–73 (2011)Google Scholar (“Accordingly, in determining the content of CIL with regard to the treatment of foreign investment, it is appropriate to focus on the practices of the major capital importing and exporting countries, which presumably constitute the relevant ‘specially affected States.’”).

⁹⁹ Treves, Tulio, Customary International Law, in 9 Max Planck Encyclopedia of Public International Law, at para. 36 (Wolfrum, Rudiger ed., 2012)Google Scholar (“Similarly, rules on economic relations, such as those on foreign investment, require practice of the main investor States as well as that of the main States in which investment is made.”).

¹⁰⁰ Akehurst, supra note 11, at 16 n. 6.

¹⁰¹ Statement by Dire Tladi on the Second Report of the Special Rapporteur on the Identification of Customary International Law (on file with author). For a summary view, see the Provisional Summary Record of the 3225th Meeting of UN International Law Commission, July 17, 2014, 10:00 am, UN Doc. A/CN.4/SR.3225.

¹⁰² Alan Boyle & Christine Chinkin, The Making of International Law 29–30 (2007); cf. Tom Ruys, “Armed Attack” and Article 51 of the UN Charter: Evolutions in Customary Law and Practice 44–45 (2010) (deeming specially affected, for purposes of the jus ad bellum, “those States which are in a position to participate in the practice under consideration and/or which have an interest in the subject matter”).

¹⁰³ Dr. Rahmat Mohamad, Secretary-General, AALCO, Address at the AALCO Legal Advisors Meeting, Identification of Customary International Law (Oct. 29, 2015), available at http://www.aalco.int/Sg%20new%20york%20address%20%202015.Pdf.

¹⁰⁴ This is, of course, a generalization. Some states traditionally considered part of the Global South are quite powerful, such as China or Brazil, while some states traditionally considered part of the Global North are quite weak, such as Croatia or Bermuda. Moreover, even weak states can initiate the development of custom by engaging in practice. An example is the exclusive economic zone (EEZ), which “was not initiated—and was indeed originally opposed—by major maritime powers.” Mendelson, Maurice H., The Objective Element in Customary International Law, 272 Recueil des Cours 226 (1998)Google Scholar.

¹⁰⁵ See, e.g., ILA Custom Report, supra note 79, at 26; Yee, Report on the ILC Project, supra note 67, at 390 (“[T]he concept of specially affected States is not reserved for the big and powerful States, but applies to all States who are specially concerned with the subject matter under consideration and whose interests are specially affected by the rule under consideration. A State need not be big and powerful to be specially affected.”); Ruys, supra note 102, at 45 (“Some authors interpret the concept of specially affected States as implying that the practice of more powerful or dominant States would have a greater impact on the development of customary rules. In accordance with the principle of sovereign equality, there is no intrinsic reason why larger States should exercise a greater influence on the customary process.”); Pearce, Jeremy, Customary International Law: Not Merely Fiction or Myth, 2003 Austl. Int'l L.J. 125, 129 n. 16 (2003)Google Scholar (“[W]hilst one could argue that more powerful states may be more likely to be specially affected since they tend to participate more regularly in different theatres of international law and relations … this cannot counter the ‘process’ by which customary law pays particular attention to interests of ‘specially affected’ states irrespective of their power.”)

¹⁰⁶ Statement by Mr. Xu Hong, Chinese Delegate, Director-General of the Department of Treaty and Law of the Ministry of Foreign Affairs of China, at the 69th Session of the UN General Assembly (Oct. 29, 2014), available at http://www.china-un.org/eng/hyyfy/t1205398.htm.

¹⁰⁷ Yee makes a version of this argument. See Yee, Report on the ILC Project, supra note 67, at 389 (arguing that because specially-affected states “may have to shoulder greater burden than others … [n]aturally their concerns and their conduct deserve special consideration”). Hugh Thirlway does, as well. See Hugh Thirlway, II The Law and Procedure of the International Court of Justice: Fifty Years of Jurisprudence 1195 (2013) (noting that nuclear states have more to lose from custom prohibiting the use of nuclear weapons than non-nuclear states).

¹⁰⁸ See text accompanying notes 215–218 infra.

¹⁰⁹ See text accompanying notes 251–257 infra.

¹¹⁰ See, e.g., Henderson, Christian, The 2010 United States National Security Strategy and the Obama Doctrine of “Necessary Force,” 15 J. Conflict & Sec. L. 403, 422 (2010)Google Scholar (“[F]orcible responses on the territory of a state have traditionally only been permissible if the actions of the non-state entities can be attributed to the territorial state.”); Tams, Christian J., The Use of Force Against Terrorists, 20 Eur. J. Int'l L. 359, 368 (2009)Google Scholar (noting that, traditionally, “[f]or an attack to qualify as an ‘armed attack’ in the sense of Article 51 (or its customary equivalent), the direct attack by a non-state actor had to be attributed to another state under rather stringent rules on attribution”); Corten, Olivier, The “Unwilling or Unable” Test: Has it Been, and Could it Be, Accepted?, 29 Leiden J. Int'l L. 777, 791 (2016)CrossRefGoogle Scholar (“Nothing would preclude the international community of states as a whole to gradually tolerate or even accept this kind of argument. This, however, would imply a radical change in the existing jus contra bellum.”); Starski, Paulina, Right to Self-Defense, Attribution and the Non-state Actor—Birth of the “Unable or Unwilling” Standard?, 75 ZaöRV 455, 496 (2015)Google Scholar (arguing that “all arguments put forward in order to base attribution within Art. 51 on unwillingness or inability ultimately fail to convince de lege lata”); Armed Activities on the Territory of the Congo (Dem. Rep. Congo/Uganda), Judgment, 2005 ICJ Rep. 168, 173 (Dec. 19) (Separate Opinion of Judge Simma) (noting that “a restrictive reading of Article 51 might well have reflected the state, or rather the prevailing interpretation, of the international law on self-defence for a long time”).

¹¹¹ Some scholars believe that the “unwilling or unable” test is already de lege lata. See, e.g., Deeks, Ashley S., “Unwilling or Unable”: Toward a Normative Framework for Extraterritorial Self-Defense, 3 Va. J. Int'l L. 483, 488 (2012)Google Scholar; Henriksen, Anders, Bellum, Jus ad and American Targeted Use of Force to Fight Terrorism Around the World, 19 J. Conflict & Sec. L. 211, 228 (2014)Google Scholar. But this is the minority position.

¹¹² The experience rationale might favor states in the Global North, which have generally existed longer than most states in the Global South and thus have had more opportunity to develop the kind of experience with a practice that justifies specially-affected status. Determining whether and to what extent such an asymmetry exists is beyond the scope of this article, but the possibility is worth noting.

¹¹³ Bellinger, John B. III & Padmanabhan, Vijay M., Detention Operations in Contemporary Conflicts: Four Challenges for the Geneva Conventions and Other Existing Law, 105 AJIL 201, 243 (2011)Google Scholar.

¹¹⁴ Every state in the world operates embassies and consulates in other states.

¹¹⁵ The Geneva Conventions, for example, are universally ratified.

¹¹⁶ Cf. Ruys, supra note 102, at 45 (rejecting the idea that “the concept of ‘specially affected States’ is applicable in each and every situation” because “certain treaties such as the Vienna Convention on the Law of Treaties or the Vienna Conventions on Diplomatic and Consular Relations would seem to be of equal importance to all members of the international community”); Danilenko, supra note 4, at 95–96 (“It is clear … that a number of general legal issues, such as the law of treaties, are of direct interest for every state.”); Villiger, supra note 64, at 14 (“How can one assess the practice of ‘affected’ States upon the 1961 and 1963 Vienna Conventions, if virtually all States entertain diplomatic and consular relations?”).

¹¹⁷ For specificity, see text accompanying notes 142–144 infra; for intensity, see text accompanying notes 156–160 infra.

¹¹⁸ Military and Paramilitary Activities in and Against Nicaragua, supra note 26, at 98, para. 186; see also Kammerhofer, Jorg, Uncertainty in the Formal Sources of International Law: Customary International Law and Some of Its Problems, 15 Eur. J. Int'l L. 523, 532 (2004)CrossRefGoogle Scholar (“Why would violations not be eligible as state practice? Customs (behavioural regularities) have no ‘legality’ for their purpose as building-blocks of (new) law. The act has two meanings, given to it by two different norms… . I do not see a logical contradiction in saying that the wearing of a green hat is to be punished and that it is part of law-making; there are two norms at work here.”).

¹¹⁹ See, e.g., Michael Byers & Simon Chesterman, Changing the Rules About Rules? Unilateral Humanitarian Intervention and the Future of International Law, in Humanitarian Intervention: Ethical, Legal and Political Dilemmas 177, 188 (J.L. Holzgrefe & Robert O. Keohane eds., 2003).

¹²⁰ See, e.g., Akehurst, supra note 11, at 8 (“[A]s an alternative to changing customary law by breaking it, States can change it by repeatedly declaring that the old rule no longer exists-a much more desirable way of changing the law.”).

¹²¹ See, e.g., Danilenko, supra note 4, at 86–87 (“From a broad political legal perspective, the emphasis on actual practice made custom a source of law which tended to reflect preferences of those powerful states that were able to assert a particular rule of conduct in inter-state relations.”); Kelly, J. Patrick, The Twilight of Customary International Law, 40 Va. J. Int'l L. 449, 505 (2000)Google Scholar (“The ‘acts-only’ jurisprudence gives lawmaking authority to the more powerful states while disenfranchising other members of the world community.”); Byers & Chesterman, supra note 119, at 188 (noting that an emphasis on physical practice “provides a substantial advantage to powerful states in developing customary international law”).

¹²² Jurisdictional Immunities, supra note 27, at 123, para. 55 (deeming state practice to include “the statements made by States, first in the course of the extensive study of the subject by the International Law Commission and then in the context of the adoption of the United Nations Convention”).

¹²³ Fourth ILC Report on Custom, supra note 7, at 77 (Draft Conclusion 6) (“Practice may take a wide range of forms. It includes both physical and verbal acts.”).

¹²⁴ ILA Custom Report, supra note 79, at 14 (“Verbal acts, and not only physical acts, of States count as State practice.”).

¹²⁵ Restatement Third, supra note 93, at §102 cmt. b (“‘Practice of states’ … includes diplomatic acts and instructions as well as public measures and other governmental acts and official statements of policy, whether they are unilateral or undertaken in cooperation with other states.”).

¹²⁶ See, e.g., Danilenko, supra note 4, at 88 (noting that the recognition of verbal statements as state practice “reflect[s] the quest of the developing countries for equal participation in community law-making”); Anghie, Antony & Chimni, B.S., Third World Approaches to International Law and Individual Responsibility in Internal Conflicts, 2 Chinese J. Int'l L. 77, 81 (2003)Google Scholar (noting that “the Third World states attempted, in effect, to formulate a new approach to sources doctrine by arguing that General Assembly resolutions passed by vast majorities had some binding legal effect”); cf. Kelly, supra note 121, at 505 (“If statements such as U.N. declarations can alone create international law, then the less powerful have a strong voice in customary law formation.”).

¹²⁷ Akehurst, supra note 11, at 8.

¹²⁸ See text accompanying notes 161–167 infra.

¹²⁹ Military and Paramilitary Activities in and Against Nicaragua, supra note 26, at 109, para. 207.

¹³⁰ See Section V(A) infra.

¹³¹ See Akehurst, supra note 11, at 8 (noting that trying to modify custom by engaging in unlawful physical practice is far more destabilizing to “the rule of law in international relations” than trying to modify it “by repeatedly declaring that the old law no longer exists”).

¹³² Ferdinandusse, Ward, Book Review, 53 Neth. Int'l L. Rev. 502, 504 (2006)Google Scholar.

¹³³ See, e.g., Erika de Wet, Invoking Obligations Omnes, Erga in the Twenty-First Century: Progressive Developments Since Barcelona Traction, 38 S. Afr. Y.B. Int'l L. 1, 6 (2013)Google Scholar.

¹³⁴ Rome Statute of the International Criminal Court, Art. 7(2)(h), July 17, 1998, 2187 UNTS 90.

¹³⁵ South Africa, it is worth noting, never claimed that status. At most it claimed to be a persistent objector. See, e.g., James A. Green, The Persistent Objector Rule in International Law 198 (2016) (noting that South Africa explicitly described itself as a persistent objector in the South-West Africa cases).

¹³⁶ Vienna Convention on the Law of Treaties, Art. 53, May 23, 1969, 1155 UNTS 331, 8 ILM 679 [hereinafter VCLT].

¹³⁷ See e.g., d'Amato, Anthony, It's a Bird, It's a Plane, It's Jus Cogens!, 6 Conn. J. Int'l L. 1, 5 (1990)Google Scholar.

¹³⁸ VCLT, supra note 136, Art. 53.

¹³⁹ This response, of course, raises another important question: if states that engage in an abhorrent practice like genocide qualify as specially affected, could a jus cogens norm prohibiting genocide have developed without their support? Most positivists agree with de Wet that in order to acquire peremptory status, “a norm … first [has to be] recognised as customary international law, whereafter the international community of States as a whole further agrees that it is a norm from which no derogation is permitted.” Erika de Wet, Jus Cogens and Obligations Erga Omnes, in The Oxford Handbook of International Human Rights Law 542 (Dinah Shelton ed., 2013); see also Domingues v. United States, Merits, Inter-Am. Ct. H.R. (ser. C) No. 12.285, paras. 49–50 (Oct. 22, 2002) (“[W]hile based on the same evidentiary sources as a norm of customary international law, the standard for determining a principle of jus cogens is more rigorous, requiring evidence of recognition of the indelibility of the norm by the international community as a whole.”). Specially-affected states doctrine and the doctrine of jus cogens can coexist, therefore, only if a jus cogens norm can form over the objections of a lone specially-affected state or a small number of specially-affected states. There is nothing theoretically incoherent about that position; in fact, Samoa specifically endorsed it in the Nuclear Weapons case. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, Verbatim Record, Statement by Samoa, CR 95/31, at paras. 49–50 (Nov. 13, 1995) [hereinafter Samoa Statement] (“Was it necessary for a general norm, a jus cogens norm, of non-discrimination to emerge (or a particular norm against apartheid) that South Africa (and perhaps Portugal and Southern Rhodesia too) must agree? South Africa surely regarded itself as the State most “specially affected.” The world did not wait for its acquiescence!”). At least one scholar, however, has suggested that a customary prohibition cannot rise to the level of jus cogens if even one specially-affected state insists on the legality of the practice:

Danilenko, supra note 4, at 236.

¹⁴⁰ See Section V(C) infra.

¹⁴¹ See Section IV(B)(2) infra.

¹⁴² O'Keefe, Roger, An “International Crime” Exception to the Immunity of State Officials from Foreign Criminal Jurisdiction: Not Currently, Not Likely, 109 AJIL Unbound 167, 168 (2015)Google Scholar.

¹⁴³ Schmitt & Vihul, supra note 90, at 25.

¹⁴⁴ Guldahl, Camilla G., The Role of Persistent Objection in International Humanitarian Law, 77 Nordic J. Int'l L. 51, 76 (2008)Google Scholar.

¹⁴⁵ Long, William J. & Grillot, Suzette R., Ideas, Beliefs, and Nuclear Policies: The Cases of South Africa and Ukraine, 7 Nonproliferation Rev. 24, 33 (2000)CrossRefGoogle Scholar.

¹⁴⁶ See id. at 34–35.

¹⁴⁷ See Post, supra note 86, at 142 (“If an emerging rule in respect to the use of sophisticated weaponry is considered then the practice of only a few states technically capable of production may suffice. For practice regarding an emerging rule on chemical weapons, the practice of many more states is of relevance.”).

¹⁴⁸ See also Ruys, supra note 102, at 44–45 (taking the position that the rule announced in North Sea Continental Shelf means that “primary attention should go to the actions of those States which are in a position to participate in the practice under consideration”).

¹⁴⁹ See text accompanying note 20 supra.

¹⁵⁰ North Sea Continental Shelf Judgment, supra note 1, at 227 (Dissenting Opinion of Judge Lachs)

¹⁵¹ Id. Judge Lachs got his math wrong. Seven ratifying states were landlocked. (He thought the number was five. Id.) So in fact only 46% of specially-affected states had ratified.

¹⁵² Cf. Doswald-Beck, Louise, Developments in Customary International Humanitarian Law, 15 Swiss. Rev. Int'l & Eur. L. 471, 487 (2005)Google Scholar (noting that, according to the experts the ICRC consulted, such states should be considered no less specially affected than states that have already developing blinding laser weapons).

¹⁵³ This is almost certainly why the ICRC considers states developing a particular weapon to be specially affected. See, e.g., I ICRC Study, supra note 97, at xliv (“Who is ‘specially affected’ will vary according to circumstances. Concerning the question of the legality of the use of blinding laser weapons, for example, ‘specially affected States’ include those identified as having been in the process of developing such weapons.”).

¹⁵⁴ Restatement Third, supra note 93, §102 rep. n. 2.

¹⁵⁵ Thirlway, supra note 88, at 71 n. 29. Thirlway thus suggests that, “[i]n this context, the States whose interests are specially affected would presumably be those which are actually or potentially in control of the economic and scientific assets necessary for the exploration of space.” Id. at 72.

¹⁵⁶ I ICRC Custom Study, supra note 97, at xlv.

¹⁵⁷ Bellinger & Haynes, supra note 73, at 445 n. 4.

¹⁵⁸ John B. Bellinger III, The Work of the Office of the Legal Adviser, Opinio Juris (Jan. 2007), available at https://www.state.gov/s/l/2007/116111.htm.

¹⁵⁹ American Bar Association, House of Delegates Resolution and Report 6 (Aug. 9, 2004), available at https://www.americanbar.org/content/dam/aba/migrated/intlaw/policy/crimeextradition/universaljurisdiction.authcheckdam.pdf (“Just as coastal states are the primary relevant states for purposes of customary law on maritime territorial boundaries, states with forces experienced in armed conflict are the primary relevant states for purposes of the customary international law of war.”).

¹⁶⁰ See Doswald-Beck, supra note 152, at 475 (“There was a discussion with both the Steering Committee and the experts consulted on whether the practice of States regularly involved in conflict, in particular the United States, should be given greater weight than other practice. The general view was negative … .”).

¹⁶¹ See, e.g., ILA Custom Report, supra note 79, at 26 (“Given the scope of their interests, both geographically and ratione materiae, they often will be ‘specially affected’ by a practice … .”); Michael Byers, Custom, Power and the Power of Rules: International Relations and Customary International Law 38 (2003) (noting that “powerful States, given the broader range and greater frequency of their activities, are more likely than less powerful States to have interests which are affected by any particular legal development”); Ruys, supra note 102, at 45–46 (noting that “major States” are more likely to be specially affected “in a wide variety of international legal domains” because they “possess the resources to engage in physical practice for which smaller States may not have the necessary capabilities”).

¹⁶² See, e.g., Bellinger & Haynes, supra note 73, at 445.

¹⁶³ See, e.g., Townley Statement, supra note 9, at 297 (“[T]he United States agrees that ‘[p]ractice may take a wide range of forms,’ including physical acts, verbal acts and—in some circumstances—inaction, as stated in Draft Conclusion 6.”).

¹⁶⁴ See Long & Grillot, supra note 145, at 32 (explaining that South Africa dismantled its nuclear weapons to improve its political and economic ties with the West).

¹⁶⁵ Cf. Ruys, supra note 102, at 41 (“An approach that bases itself almost exclusively on physical practice presents far greater risks of arbitrariness than one that focuses on what States say. It tends to ignore rule-compliant behaviour and to downplay the (positive and negative) reactions of third States. Furthermore, it implies a great risk of subjectiveness in the sense that the interpreter will examine the practice through the lens of what he believes the State could or should have said to justify its conduct.”).

¹⁶⁶ See Restatement Third, supra note 93, at 6 (“The doctrine of the continental shelf became accepted as customary law on the basis of assertions of exclusive jurisdiction by coastal states and general acquiescence by other states, although for some years actual mining on the continental shelf (outside a state's territorial sea) was not technologically feasible.”).

¹⁶⁷ See, e.g., Thirlway, supra note 88, at 71 n. 29.

¹⁶⁸ Nuclear Weapons Advisory Opinion, supra note 28, at 535 (Dissenting Opinion of Judge Weeramantry). Judge Shahabuddeen took a similar position in his dissent: “Where what is in issue is the lawfulness of the use of a weapon which could annihilate mankind and so destroy all States, the test of which States are specially affected turns not on the ownership of the weapon, but on the consequences of its use. From this point of view, all States are equally affected, for, like the people who inhabit them, they all have an equal right to exist.” Id. at 414 (Dissenting Opinion of Judge Shahabuddeen).

¹⁶⁹ See, e.g., Mendelson, Objective Element, supra note 104, at 227 (noting that “the broad meaning of the concept ‘specially affected States’ … prevent[s] the formation of customary international rules being the sole preserve of the mighty”).

¹⁷⁰ See, e.g., Marouf, Fatma E., The Role of Foreign Authorities in U.S. Asylum Adjudication, 45 N.Y.U. J. Int'l L. & Pol. 391, 460–61 (2012–2013)Google Scholar (noting that because Global South states face the largest number of asylum claims, “[e]xamining specially affected parties in the asylum context therefore opens the door to engage more deeply with the laws and interpretations of less powerful countries, rather than simply reinforcing the views of those that already dominate the international stage”); cf. Byers, Michael, Review Essay, 97 AJIL 712, 723 (2003)Google Scholar (“It would seem equally appropriate to argue that weaker states, being much more vulnerable to applications of military force, should thus be considered ‘specially affected states’ in the sense identified in the North Sea Continental Shelf cases … .”).

¹⁷¹ See Section 4(B)(2)(a) infra.

¹⁷² Elena Chachko & Ashley Deeks, Who Is on Board with “Unwilling or Unable”?, Lawfare (Oct. 10, 2016), at https://www.lawfareblog.com/who-board-unwilling-or-unable#UnitedStates.

¹⁷³ Nuclear Weapons Advisory Opinion, supra note 28, at 536 (Dissenting Opinion of Judge Weeramantry); see also Weise, Rachel A., How Nuclear Weapons Change the Doctrine of Self-Defense, 44 N.Y.U. J. Int'l L. & Pol. 1331, 1356 (2012)Google Scholar (noting that “the non-nuclear weapons states have a valid point that all states are specially affected given the hugely destructive power of nuclear weapons”).

¹⁷⁴ Starski, Paulina, Silence Within the Process of Normative Change and Evolution of the Prohibition on the Use of Force: Normative Volatility and Legislative Responsibility, 4 J. Use of Force & Int'l L. 14, 24 (2017)Google Scholar.

¹⁷⁵ Tladi Statement, supra note 101.

¹⁷⁶ See Leslie Allen, Will Tuvalu Disappear Beneath the Sea?, Smithsonian Mag. (Aug. 2004), at www.smithsonianmag.com/science-nature/will-tuvalu-diseappear-beneath-the-sea-180940704.

¹⁷⁷ Villiger, supra note 64, at 14–15.

¹⁷⁸ Danilenko, supra note 4, at 96.

¹⁷⁹ I ICRC Study, supra note 97, at xlv.

¹⁸⁰ Draft Articles on Responsibility of States for Internationally Wrongful Acts, Rep. of the Int'l Law Comm'n on the Work of Its Fifty-Third Session, UN GAOR, 56th Sess., Supp. No. 10, at 119, UN Doc. A/56/10 (2001).

¹⁸¹ Id.

¹⁸² Peel, Jacqueline, New State Responsibility Rules and Compliance with Multilateral Environmental Obligations: Some Case Studies of How the New Rules Might Apply in the International Environmental Context, 10 Rev. of Eur. Comm. & Int'l Envtl. L. 1, 86 (2001)Google Scholar

¹⁸³ Cismas, Ioana, Secession in Theory and Practice: The Case of Kosovo and Beyond, 2 Goettingen J. Int'l L. 531, 584 (2010)Google Scholar.

¹⁸⁴ This was Iceland's situation.

¹⁸⁵ Cf. Tomuschat, Christian, Obligations Arising for States Without or Against Their Will, 241 Collected Courses Hague Acad. Int'l L. 212 (1993)Google Scholar (“All activities of a modern industrialized society have, to a greater or lesser extent, repercussions beyond the borders of the State in whose territory they are carried out, by affecting air, water and soils.”)

¹⁸⁶ Worster, William Thomas, The Evolving Definition of the Refugee in Contemporary International Law, 30 Berk. J. Int'l L. 94, 110 (2012)Google Scholar.

¹⁸⁷ This example illustrates the need to distinguish between practice and effect. Turkey's processing of refugees makes it specially affected with regard to issues of refugee law (through practice). The influx of refugees into Turkey makes it specially affected with regard to the jus in bello (through effect).

¹⁸⁸ Peel, supra note 182, at 88.

¹⁸⁹ Elodie Aba and Bobbie Sta. Maria, 100,000 May Have Died but There Is Still No Justice over Indonesian Air Pollution, Guardian (Feb. 4, 2017), at https://www.theguardian.com/global-development-professionals-network/2017/feb/04/indonesian-air-pollution-death-justice.

¹⁹⁰ Draft Articles, supra note 180, at 119.

¹⁹¹ Further efforts to define indirect effect are beyond the scope of this article. Developing workable guidelines for identifying when a state should be considered specially indirectly affected by a particular practice is a key task for future research.

¹⁹² Cf. Statement by the Netherlands, Sixty-Ninth Session of the General Assembly, para. 11 (2014) (suggesting that specially-affected status should be extended not only to “States possessing modern weapons technology,” but also to “States not possessing such technology who may face the risk of an armed conflict in which the opponent uses such new technology”).

¹⁹³ Whether the doctrine of specially-affected states applies differently to new rules and modified rules is considered below. See note 244 infra.

¹⁹⁴ “Support” equates here to opinio juris—the state's position concerning the legality of a practice.

¹⁹⁵ Shaw, supra note 95, at 56.

¹⁹⁶ Post, supra note 86, at 142.

¹⁹⁷ Thirlway, supra note 88, at 71. Bin Cheng comes close to embracing this position, although he leaves open the possibility that “effective opposition” by non-specially-affected states could block the creation of a new rule. See Bin Cheng, Opinio Juris: A Key Concept in International Law That Is Much Misunderstood, in International Law in the Post-Cold War World 56, 68 (Sienho Yee & Wang Tieya eds., 2001) (“[W]hen all the States specially affected, when all the States that really matter in the area in question, have embraced the rule, and there is no effective opposition, we then definitely have an opinio generalis juris generalis.”) What constitutes effective opposition, Bin Cheng does not say.

¹⁹⁸ North Sea Continental Shelf Judgment, supra note 1, at 42, para. 73 (emphasis added).

¹⁹⁹ ILA Custom Report, supra note 79, at 26 (“[I]f all major interests (‘specially affected States’) are represented, it is not essential for a majority of States to have participated (still less a great majority, or all of them). The negative aspect is that if important actors do not accept the practice, it cannot mature into a rule of general customary law.”).

²⁰⁰ I ICRC Study, supra note 97, at xliv (“[I]f all ‘specially affected States’ are represented, it is not essential for a majority of States to have actively participated, but they must have at least acquiesced in the practice … .”).

²⁰¹ Akehurst, supra note 11, at 22 (noting that requiring specially-affected states to engage in a practice “is not the same as saying that the practice followed by the States whose interests were specially affected could give rise to a rule of customary law if a contrary practice had been followed by other States”); Villiger, supra note 64, at 14 (rejecting the idea that “if all specially affected States engage in such practice, a customary rule must come about, since the remaining practice of other States may be sufficiently inconsistent to prevent formation of the customary rule”); Danilenko, supra note 4, at 94 (“[T]he requirement of generality presupposed that general custom must be based on practice of various groups of states representing all the constituent elements of the modern international community.”).

²⁰² North Sea Continental Shelf Judgment, supra note 1, at 227 (Dissenting Opinion of Judge Lachs) (“This mathematical computation, important as it is in itself, should be supplemented by, so to speak, a spectral analysis of the representativity of the States … . For in the world today an essential factor in the formation of a new rule of general international law is to be taken into account: namely that States with different political, economic and legal systems, States of all continents, participate in the process.”).

²⁰³ See, e.g., Tladi Statement, supra note 101 (“Even with respect to … the continental shelf, where it could be argued that States without a continental shelf couldn't be specifically affected, the fact that the extension of the continental shelf will affect the extent of the Area (or deep Seabed) shows how limited such a view is.”); Tomuschat, supra note 185, at 212 (“All activities of a modern industrialized society have, to a greater or lesser extent, repercussions beyond the borders of the State in whose territory they are carried out, by affecting air, water and soils.”).

²⁰⁴ See, e.g., I ICRC Study, supra note 97, at xlv (“Notwithstanding the fact that there are specially affected States in certain areas of international humanitarian law, it is also true that all States have a legal interest in requiring respect for international humanitarian law by other States, even if they are not a party to the conflict.”).

²⁰⁵ See, e.g., id. (noting that, because of the universal legal interest in respect for international humanitarian law, “the practice of all States must be considered, whether or not they are ‘specially affected’ in the strict sense of that term.”); Nuclear Weapons Advisory Opinion, supra note 1, at 278 (Declaration of Judge Shi) (“The appreciable section of this community to which the Opinion refers by no means constitutes a large proportion of that membership, and the structure of the international community is built on the principle of sovereign equality. Therefore, any undue emphasis on the practice of this ‘appreciable section’ would … be contrary to the very principle of sovereign equality of States … .”); Tomuschat, supra note 185, at 291 (“The minimum threshold of general acceptance is reached only when all major groups of States have, through their practice, shown that a given pattern of conduct encapsulates an equitable balance of interests.”).

²⁰⁶ See, e.g., Mendelson, Objective Element, supra note 104, at 227 (noting that “the requirement of representativeness prevent[s] the formation of customary international rules being the sole preserve of the mighty”).

²⁰⁷ The number of such states is notoriously uncertain and context-dependent. See, e.g., ILA Custom Report, supra note 79, at 25 (“Given the inherently informal nature of customary law, it is not to be expected, neither is it the case, that a precise number or percentage of States is required. Much will depend on circumstances and, in particular, on the degree of representativeness of the practice.”). Both the ILA and the ICRC take the position that less than a majority of the world's states is sufficient. See id. at 26 (“[I]if all major interests (‘specially affected States’) are represented, it is not essential for a majority of States to have participated (still less a great majority, or all of them)”); I ICRC Study, supra note 97, at xliv (“[I]f all ‘specially affected States’ are represented, it is not essential for a majority of States to have actively participated, but they must have at least acquiesced in the practice of ‘specially affected States’.”). A thorough analysis of the issue, however, is beyond the scope of this article.

²⁰⁸ See, e.g., Restatement Third, supra note 93, §102 cmt. b (“Inaction may constitute state practice, as when a state acquiesces in acts of another state that affect its legal rights.”); ILA Custom Report, supra note 79, at 26 (“‘Practice’ here includes acquiescence.”); I ICRC Study, supra note 97, at xliv (“[I]f all ‘specially affected States’ are represented, it is not essential for a majority of States to have actively participated, but they must have at least acquiesced in the practice of ‘specially affected States.’”)

²⁰⁹ North Sea Continental Shelf Judgment, supra note 1, at 227; see also Tomuschat, supra note 185, at 291 (“The minimum threshold of general acceptance is reached only when all major groups of States have, through their practice, shown that a given pattern of conduct encapsulates an equitable balance of interests.”); Danilenko, Gennady M., The Theory of International Customary Law, 31 German Y.B. Int'l L. 9, 30 (1988)Google Scholar (“[A]n important prerequisite, resulting from the generality requirement, is that participation in the practice leading to the creation of general customary rules must in one way or another include States with different political, economic and legal systems and States of all continents.”).

²¹⁰ Thirlway, supra note 88, at 72.

²¹¹ Id.

²¹² See, e.g., Restatement Third, supra note 93, §102 rep. n. 2 (“The Outer Space Declaration, for example, might have become law even if a formal treaty had not followed, since it was approved by all, including the principal ‘space powers.’”)

²¹³ See, e.g., Oppenheim, Jesse, Danger at 700,000 Feet: Why the United States Needs to Develop a Kinetic Anti-satellite Missile Technology Test-Ban Treaty, 38 Brook. J. Int'l L. 761, 768 (2012–2013)Google Scholar (“Ratified by nearly 100 countries, the Outer Space Treaty of 1967 … uses the same wording of the ‘Principles Declaration’ in its preamble and confirms the fundamental principles that outer space is ‘the province of all mankind.’”).

²¹⁴ See ILA Custom Report, supra note 79, at 26 (noting that the “negative” aspect of the representativeness requirement “is that if important actors do not accept the practice, it cannot mature into a rule of general customary law”).

²¹⁵ See, e.g., Danilenko, supra note 4, at 89 (“Thus, the developing countries of the Group of 77 claimed that the principle of common heritage of mankind, which excludes unilateral exploitation of the international resources of the deep seabed, has ripened into a norm of customary law.”).

²¹⁶ See Arrow, Dennis W., Seabeds, Sovereignty, and Objective Regimes, 7 Fordham Int'l L.J. 169, 226–27 (1983–1984)Google Scholar.

²¹⁷ Arrow, Dennis W., The Customary Norm Process and the Deep Seabed, 9 Ocean Dev. & Int'l L.J. 1, 36–37 (1981)CrossRefGoogle Scholar; see also Tanaka, Yoshifuma, Protection of Community Interests in International Law: The Case of the Law of the Sea, 15 Max Planck Y.B. UN L. 329, 346 (2011)Google Scholar (identifying states).

²¹⁸ See Arrow, Customary Norm Process, supra note 217, at 38 (noting that the rule has failed “to achieve a qualitative consensus among the specially affected states”); Tanaka, supra note 217, at 346; Joyner, Christopher C. & Martell, Elizabeth A., Looking Back to See Ahead: UNCLOS III and Lessons for Global Commons Law, 27 Ocean Dev. & Int'l L. 73, 79 (1996)CrossRefGoogle Scholar.

²¹⁹ Rees-Evans, Laura, Secession and the Use of Force in International Law, 4 Cambridge Student L. Rev. 249, 258 (2008–2009)Google Scholar; cf. Yee, Sienho, Notes on the International Court of Justice (Part 4): The Kosovo Advisory Opinion, 9 Chinese J. Int'l L. 763, 778 (2010)Google Scholar (noting that “the strong oppositions to the claimed right of self-determination or remedial secession put forward by those specially affected States which have to endure any potential fallout, and the half-hearted ‘secondary argument’ of those States little touched by and situated far away from the claimed right all militate against the finding of an opinio juris supporting such a claimed right”).

²²⁰ See, e.g., Green, supra note 135, at 198. Scholars disagree about whether South Africa qualified as a persistent objector to the customary prohibition of apartheid, despite the unwillingness of the international community to recognize it as one. Compare id. (noting that South Africa and the unrecognized state of Rhodesia “maintained a degree of persistent objection to this customary prohibition, both by way of ‘deed’ (through their continuance of the policy) and declarations that they were not bound by the customary norm”) with Schachter, Oscar, International Law in Theory and Practice, 178 Recueil des Cours 119 (1982)Google Scholar (arguing that South Africa was not a persistent objector because it had consented to the principle of racial equality in Article 55 of the UN Charter). Elias describes South Africa as having engaged in “disguised persistent objection.” Elias, Olufemi, Some Remarks on the Persistent Objector Rule in Customary International Law, 6 Denning L.J. 37, 46–47 (1991)Google Scholar. The debate is not germane to the issue here, which concerns what happens when a lone state specially-affected state objects to a crystallizing customary rule.

²²¹ See, e.g., de Wet, Invoking Obligations Erga Omnes, supra note 133, at 7 (“The better view is that in order to acquire peremptory status, a norm first has to be recognised as customary international law, whereafter the international community of States as a whole further agrees that it is a norm from which no derogation is permitted.”).

²²² See Samoa Statement, supra note 139, at 49–50.

²²³ Such states include Bhutan, Central African Republic, Comoros, Haiti, and the Sudan, all of which have criminalized torture despite being under no conventional obligation to do so. See Status of Ratifications Interactive Dashboard, Convention Against Torture, available at http://indicators.ohchr.org.

²²⁴ See, e.g., Kelly, supra note 121, at 474 (listing problems); Mendleson, Maurice, The Subjective Element in Customary International Law, 66 Brit. Y.B. Int'l L. 177, 186–87 (1996)Google Scholar (arguing that “it is simply not true that all of those who failed to protest can reasonably be taken to have acquiesced”).

²²⁵ Maurice Mendelson, Subjective Element, supra note 224, at 186; see also Lauterpacht, Hersch, Sovereignty over Submarine Areas, 27 Brit. Y.B. Int'l L. 376, 397–98 (1950)Google Scholar (claiming that “any such duty to protest is especially incumbent upon states directly interested—in the case of the proclamations relating to submarine areas in particular upon neighbouring states …”); Starski, Silence Within the Process, supra note 174, at 22 (“In the context of individual inter-state relationships (for example, acquisitory prescription), specially affected states are deemed to have acquiesced if they do not protest.”); Ruys, supra note 102, at 38 (inferring from ICJ jurisprudence that “acquiescence matters most when it emanates from States directly concerned with a concrete recourse to force”); Kelly, supra note 121, at 473 (“At most, acquiescence furnishes some evidence of the attitude of a few states. It is insufficient to demonstrate general acceptance unless the vast majority of states have failed to protest when a norm has been asserted against their immediate interests.”).

²²⁶ Fisheries Jurisdiction, supra note 25, at 90–91.

²²⁷ ILA Custom Report, supra note 79, at 26.

²²⁸ Peter Malanczuk, Akehurst's Modern Introduction to International Law 42 (7th ed. 1997).

²²⁹ Schmitt & Vihul, supra note 90, at 25.

²³⁰ Torsten Gihl mentions an example of one specially-affected state being able to resist the formation of a customary rule supported by nearly all other specially-affected states: the United Kingdom “prevent[ing] the rule that neutral convoys were immune from search from becoming a general rule of international law, although it was accepted by practically all the Continental powers.” Gihl, Torsten, The Legal Character and Sources of International Law, 1 Scand. Stud. L. 51, 82 (1957)Google Scholar. As Gihl notes, though, the United Kingdom was able to resist the rule because it was the “strongest naval power” and was willing to use force to ensure that other states accepted its position. Id. Such opposition would not be possible in the modern era, in which the use of force is so carefully regulated.

²³¹ Simpson, supra note 57, at 48.

²³² The ILA, ILC, and AALCO Informal Expert Group each accept the possibility of persistent objection. ILA Custom Report, supra note 79, at 27; Fourth ILC Custom Report, supra note 7, at 79 (Draft Conclusion 15); Yee, Report on the ILC Project, supra note 67, at 391 (noting that, at the first meeting of the Informal Expert Group, “the importance of the persistent objector rule was stressed and a recommendation was made that the Group should address this issue”). A number of scholars do, as well. See, e.g., Malanczuk, supra note 228, at 43; Villiger, supra note 64, at 33–37; Ian Brownlie, Principles of Public International Law 4–11 (4th ed. 1990); Mendelson, Objective Element, supra note 104, at 238. Other scholars reject the possibility. See, e.g., Stein, Ted L., The Approach of the Different Drummer: The Principle of the Persistent Objector in International Law, 26 Harv. Int'l. L.J. 457, 459–63 (1985)Google Scholar; Charney, Jonathan I., Universal International Law, 87 AJIL 529, 540 (1993)CrossRefGoogle Scholar (“[S]tate practice and other evidence do not support the existence of the persistent objector rule.”); Kelly, supra note 121, at 508 (“The persistent objector principle, far from being an integral part of CIL theory, is a new concept and one of doubtful pedigree.”).

²³³ A state that has developed or is developing such weapons, according to the ICRC. See Doswald-Beck, supra note 152, at 486–87. No state qualifies as specially affected via effect, because such weapons have not yet been used in combat. See Dan Drolette, Jr., Blinding Them with Science: Is Development of a Banned Laser Weapon Continuing?, Bull. Atomic Scientists (Sept. 14, 2014), at https://thebulletin.org/blinding-them-science-development-banned-laser-weapon-continuing7598.

²³⁴ Doswald-Beck, supra note 152, at 486–87.

²³⁵ North Sea Continental Shelf Judgment, supra note 1, at 43, para. 74 (emphasis added).

²³⁶ Quoted in Danilenko, supra note 4, at 95 n. 66.

²³⁷ Hulme, supra note 92, at 233.

²³⁸ Rudiger Wolfrum, Comment, in United States Hegemony, supra note 13, at 359–60.

²³⁹ Mendelson is correct to insist, of course, that how to strike the correct balance between specially-affected states and non-specially-affected states is an “ultimately political question.” Mendelson, Objective Element, supra note 104, at 227.

²⁴⁰ North Sea Continental Shelf Judgment, supra note 1, at 227.

²⁴¹ Fisheries Jurisdiction, supra note 25, at 221–22 (Joint Separate Opinion).

²⁴² U.S. Letter, supra note 29, at 18–19 (“[S]uch General Assembly resolutions could only be declarative of the existence of principles of customary international law to the extent that such principles had been recognized by the international community, including the States most directly affected. In fact … these resolutions were not accepted by a majority of the nuclear-weapon States.”).

²⁴³ Nuclear Weapons Advisory Opinion, supra note 28, at 319 (Dissenting Opinion of Judge Schwebel).

²⁴⁴ Some scholars suggest that modifying an existing rule of custom requires more state practice than creating a new customary rule. See, e.g., Akehurst, supra note 11, at 19 (“The better established a rule is (i.e. the more frequent, long-standing, and widespread the practice which supports it), the greater the quantity of practice needed to overturn it. Conversely, a new rule which differs only slightly from the pre-existing rule can be established more easily than a rule which is radically different from the pre-existing rule.”); Mendelson, Objective Element, supra note 104, at 222–23 (“Obviously, the amount of practice required to overturn an old rule will be greater than in cases where the matter has not previously been the subject of specific regulation in international law; but even in the latter instance, it must be sufficiently general.”) That is, however, anything but a universal view. Some scholars insist that there is no difference between custom modification and custom creation. See, e.g., Treves, supra note 99, para. 3 (“[T]he process through which customary rules are modified or extinguished is the same as that through which they come into being.”). Others believe that the practice requirement is the same but that greater evidence of opinio juris is required for custom modification. See, e.g., Danilenko, supra note 209, at 45 (“[S]tricter requirements ought to be applied in respect of evidence of the existence of opinio iuris as compared with, for example, the situations where new customary norms emerge with regard to problems that previously were not regulated by international law.”). Although a satisfactory analysis is beyond the scope of this article, the “more practice” position seems difficult to reconcile with the ICJ's approach to custom formation. In the Nicaragua case, for example, the ICJ explicitly addressed a potential modification of the customary principle of non-intervention. Military and Paramilitary Activities in and Against Nicaragua, supra note 26, at 108, para. 206 (noting that the United States was arguing for “a fundamental modification of the customary law principle of non-intervention”). Yet the Court did not suggest that custom modification required more practice than custom creation. On the contrary, it simply repeated the North Sea Continental Shelf mantra about settled practice being required. Id.

Even if the “more practice” position is correct, it is difficult to see why that would affect the doctrine of specially-affected states. Presumably the argument would be that although support by a bare majority of specially-affected states is required to create a new rule of custom, modifying an existing customary rule requires more—a supermajority, say. But why should the sovereign-equality based need to treat specially-affected states as legislatively equal inter se give way simply because the majority wants to modify a customary rule instead of create a new one? The “more practice” argument not only penalizes specially-affected states for changing their mind about the desirability of a particular customary rule, it also penalizes states that do not become specially affected (either through practice or distinctive effect) until after the rule has crystallized. The doctrine of specially-affected states as understood in this article seems conservative enough, unless we ascribe exceptional importance to the stability of customary international law—a position that is difficult to reconcile with the ascendance of modern custom, which is designed to promote rapid legal development. See generally Roberts, Anthea Elizabeth, Traditional and Modern Approaches to Customary International Law: A Reconciliation, 95 AJIL 757, 758 (2001)CrossRefGoogle Scholar. If the “more practice” position is correct, therefore, it should be interpreted to require more non-specially-affected states to support the customary rule, not more specially-affected ones.

²⁴⁵ Byers & Chesterman, supra note 119, at 182–83.

²⁴⁶ Id. at 186.

²⁴⁷ See Statement by Niels Helveg Petersen, Minister of Foreign Affairs for Denmark, to the United Nations 55th General Assembly, at http://www.un.org/ga/webcast/statements/denmarkE.htm.

²⁴⁸ For example, Germany and Belgium specifically disavowed unilateral humanitarian intervention (UHI) as a justification for NATO's intervention in Kosovo, even though they participated in it. See Lowe, Vaughan & Tzanakopoulos, Antonios, Humanitarian Intervention, 4 Max Planck Encyclopedia of Public International Law, at para. 32 (Wolfrum, Rudiger ed., 2012)Google Scholar.

²⁴⁹ See, e.g., Byers & Chesterman, supra note 119, at 183 (“The few interventions that might have been justified on a humanitarian basis—Bangladesh, Cambodia, Uganda—were justified on other terms, while interventions in Liberia, Somalia, Bosnia, Haiti, and Rwanda were conducted on the basis of Security Council authorizations, and in some cases also at the invitation of the targeted state.”); see also Lowe & Tzanakopoulos, supra note 248, para. 29 (noting that UHI was not invoked by the states intervening in Somalia, Rwanda, East Timor, Liberia, Sierra Leone, East Pakistan, Tanzania, and Vietnam).

²⁵⁰ Byers & Chesterman, supra note 119, at 183–84; see also Lowe & Tzanakopoulos, supra note 248, para. 33 (“The Non-Aligned Movement (NAM), numbering well over half of the Member States of the UN, unequivocally condemned the use of force against the (then) FRY, as did many other States, some of which are nuclear powers.”).

²⁵¹ See, e.g., BE v. Sec. of State, [2007] UKAIT 35, para. 62, at https://tribunalsdecisions.service.gov.uk/utiac/37892 (noting that specially-affected states include “States that historically have produced, traded in or deployed landmines”).

²⁵² See, e.g., Price, supra note 61, at 121 (“If any states were to be regarded in a meaningful sense as ‘specially affected,’ it would be those with enormous landmine problems … .”).

²⁵³ See generally Landmine Monitor 2014, at http://www.the-monitor.org/en-gb/reports/2014/landmine-monitor-2014/major-findings.aspx.

²⁵⁴ Malanczuk, supra note 228, at 37.

²⁵⁵ Price, supra note 63, at 121.

²⁵⁶ The list includes the United States, India, China, Russia, Pakistan, Iran, Iraq, North Korea, South Korea, Cuba, Israel, Libya, Syria, Egypt, Myanmar, Eritrea, Georgia, India, Israel, Kyrgyzstan, Nepal, Pakistan, Russia, Somalia, Sri Lanka, Turkey, Uzbekistan, Burundi, Ethiopia, Senegal, and Guinea-Bissau. See id. at 116–26.

²⁵⁷ Id. at 119.

²⁵⁸ See Death Penalty Information Center, Abolitionist and Retentionist Countries, at https://deathpenaltyinfo.org/abolitionist-and-retentionist-countries.

²⁵⁹ Ohlin, Jens David, Applying the Death Penalty to Crimes of Genocide, 99 AJIL 747, 756 (2005)CrossRefGoogle Scholar.

²⁶⁰ “Automatic succession, as the term is used in international law, is succession that occurs regardless of the volition of the successor state and without any steps being taken by that state. It is a succession that is both implied and obligatory.” Rasulov, Akbar, Revisiting State Succession to Humanitarian Treaties: Is There a Case for Automaticity?, 14 Eur. J. Int'l L. 141, 149–50 (2003)CrossRefGoogle Scholar.

²⁶¹ See id. at 154 (noting that useful evidence is “an extremely rare occurrence in the field of state succession”).

²⁶² Menno T. Kamminga, Preliminary Report: Human Rights Treaties and State Succession, European Commission for Democracy Through Law, at 4, CDL-UD(2005)013 (Sept. 7, 2005).

²⁶³ Kamminga, Menno T., State Succession in Respect of Human Rights Treaties, 7 Eur. J. Int'l L. 469, 473 (1996)CrossRefGoogle Scholar.

²⁶⁴ Kamminga, Preliminary Report, supra note 262, at 6.

²⁶⁵ Id. at 5.

²⁶⁶ Rasulov, supra note 260, at 158.

²⁶⁷ Id. at 158–61.

²⁶⁸ CTBTO Preparatory Commission, Status of Signature and Ratification, at https://www.ctbto.org/the-treaty/status-of-signature-and-ratification.

²⁶⁹ Tabassi, Lisa, The Nuclear Test Ban: Lex Lata or de Lege Ferenda?, 14 J. Confl. & Sec. L. 309, 321 (2009)Google Scholar.

²⁷⁰ It could be argued that the nuclear-weapons-sharing states—Belgium, Germany, Italy, Netherlands, and Turkey—also qualify as specially affected. If so, the majority supporting a comprehensive ban is even greater, because all four have ratified the CTBT. See CTBTO, supra note 268.

²⁷¹ Id.

²⁷² Tabassi, supra note 269, at 318–19.

²⁷³ Id. at 322.

²⁷⁴ Id.

²⁷⁵ The case for an equivalent customary prohibition in non-international armed conflict is very weak, as Darcy has shown. See Darcy, Shane, The Evolution of the Law of Belligerent Reprisals, 175 Mil. L. Rev. 184, 219 (2003)Google Scholar; see also Kalshoven, Frits, Belligerent Reprisals Revisited, 21 Neth. Y.B. Int'l L. 43, 78 (1990)Google Scholar (same).

²⁷⁶ Cf. Doswald-Beck, supra note 152, at 482 (“Is the practice of the US, UK and Italy enough to prevent the emergence of a rule because they are ‘specially affected’ States? This is not certain because any State has the capacity to indulge in such reprisals.”)

²⁷⁷ I ICRC Custom Study, supra note 97, at 514 (citing numerous examples).

²⁷⁸ See Section IV(A) supra.

²⁷⁹ GA Res. 2675, UN GAOR, 25th Sess., Supp. No. 28, UN Doc. A/8028 (1970).

²⁸⁰ Protocol Additional to the Geneva Conventions of 12 August 1949 and Relating to the Protection of Victims of International Armed Conflicts, Art. 51(6), June 8, 1977, 1125 UNTS 3 (“Attacks against the civilian population or civilians by way of reprisals are prohibited.”).

²⁸¹ See Guldahl, supra note 144, at 71.

²⁸² Darcy, supra note 275, at 223 (“Although not as numerous as those to the Geneva Conventions, this is still a substantial figure, and such a level of acceptance would strengthen any claim toward the customary character of norms set out therein.”).

²⁸³ See Doswald-Beck, supra note 152, at 481.

²⁸⁴ See ICRC, II Customary International Humanitarian Law: Practice 3409 (Jean-Marie Henckaerts & Louise Doswald-Beck eds., 2005).

²⁸⁵ Doswald-Beck, supra note 152, at 482.

²⁸⁶ Cf. Guldahl, supra note 144, at 75 (“[A]lthough the existence of a customary rule is not yet definite, the contrary practice of not just any State but of some of the world's major military powers has not been sufficient to prevent the rule from at least being in the process of formation.”).

²⁸⁷ Id. at 77 (noting that “it is safe to conclude that they meet the requirement of objecting from the time of formation of the rule”).

²⁸⁸ Galindo & Yip, supra note 11, at 17; see also Kelly, supra note 121, at 514 (“In the 1960s and early 1970s, as the newly independent nations became a majority at the U.N. General Assembly, Western states began to lose control of the development of customary law regimes… . The notion of the persistent objector can be seen as the Western counter-reformation to this revolution.”); Stein, supra note 232, at 471 (noting that because modern custom “may generate outcomes unfavorable to the United States … [t]he principle of the persistent objector presents a highly respectable doctrinal solution to that problem”).

²⁸⁹ Brownlie, Ian, International Law at the Fiftieth Anniversary of the United Nations, 255 Recueil des Cours 49 (1995-I)Google Scholar (“The hegemonial approach to international relations may be defined as an approach to the sources which facilitates the translation of the difference in power between States into specific advantages for the more powerful actor.”); cf. Nico Krisch, More Equal than the Rest? Hierarchy, Equality and U.S. Predominance in International Law, in United States Hegemony, supra note 13, at 153 (“The greater reach and strength of international law, however, reduces the possibilities for keeping inequalities “outside the law,” which, for centuries, had been the strategy for mitigating the effects of sovereign equality on the exercise of superior power. Powerful States therefore try to introduce inequalities into international law… . This is precisely what the United States sought during the last century.”).

²⁹⁰ This discussion assumes for the sake of argument that specially-affected states in the Global North states and Global South take the same position concerning a potential customary rule. That will not always be the case. As we have seen, Global North states are divided over blinding laser weapons and belligerent reprisals against civilians, while Global South states are divided over anti-personnel landmines.

²⁹¹ Cf. Anghie & Chimni, supra note 126, at 102 (describing Third World approaches to international law (TWAIL) as “an ongoing project that is continuously questioning not only the foundations and operations of international law, but also its own methodological premises”).