I. INTRODUCTION
While many territorial disputes have been referred to the International Court of Justice (ICJ) or other international tribunals, there are also many territorial disputes in the world that are not brought before the ICJ or other tribunals because the parties to the disputes do not accept their jurisdiction. Especially in the latter category of territorial disputes, where there is no prospect for settlement based on international law, the parties to the disputes are sometimes tempted to send military forces to the disputed territories and deter the other claimants from exercising control over them, because, if they succeed, without fearing the prospect of proceedings before the ICJ or other tribunals, they can enjoy a new status quo. While the other claimants may protest the presence of the military forces, the risk of armed conflict deters them from sending their own military forces.
In some territorial disputes referred to the ICJ, the parties to the disputes have deployed military forces in the disputed territories. One of the most recent territorial disputes referred to the ICJ where a military presence was established in a disputed territory was the case concerning Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v Nicaragua), which was combined with the case concerning Construction of a Road in Costa Rica along the San Juan River (Nicaragua v Costa Rica). In its judgment of 16 December 2015, the ICJ found: ‘Costa Rica has sovereignty over the “disputed territory” as defined by the Court.’Footnote 1 The Court also found: ‘by excavating three caños and establishing a military presence on Costa Rican territory, Nicaragua has violated the territorial sovereignty of Costa Rica’.
Costa Rica asked the ICJ to find that by occupying and claiming the Costa Rican territory Nicaragua breached the prohibition of the threat or use of force under Article 2(4) of the United Nations (UN) Charter. The ICJ said: ‘The fact that Nicaragua considered that its activities were taking place on its own territory does not exclude the possibility of characterizing them as an unlawful use of force.’Footnote 2 However, it also said:
… in the circumstances, given that the unlawful character of these activities has already been established, the Court need not dwell any further on this submission. As in the case concerning Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria Equatorial Guinea intervening), the Court finds that ‘by the very fact of the present Judgment and of the evacuation’ of the disputed territory, the injury suffered by Costa Rica ‘will in all events have been sufficiently addressed’.Footnote 3
In his separate opinion, Judge Owada argued: ‘… it is my view that it would have been more appropriate for the Court to have gone further by declaring that these internationally wrongful acts by Nicaraguan authorities constituted an unlawful use of force under Article 2(4) of the United Nations Charter’.Footnote 4 Judge Robinson concurred with Judge Owada on this matter. In his separate opinion, quoting the language of the 1970 ‘Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations’ (Friendly Relations Declaration) annexed to the General Assembly (GA) resolution 2625(XXV), he pointed out: ‘… given that the location of the boundary was subject to a case before the Court, to the extent that Nicaragua's use of force may be seen “as a means of solving international disputes”, it will violate the customary norm reflected in this duty’.Footnote 5 He also argued: ‘The jurisprudence also establishes that non-violent use of force is not exempted from the prohibition. No shots need be fired, no heavy armaments need be used and certainly no one need be killed before a State can be said to have violated the prohibition’.Footnote 6
Under Article 2(4) of the UN Charter, it is difficult for States claiming sovereignty over a land territory disputed with other States to justify the violent use of force to change the situation in the disputed territory in their favour. On the other hand, Nicaragua's activities in the disputed territory did not involve any exchange of fire and it was described as a ‘non-violent use of force’ by Judge Robinson. In the following, the use of armed force that does not cause human injury or damage to property is called ‘non-violent use of force’.Footnote 7 The text of Article 2(4) does not clarify whether the term ‘use’ of force includes the establishment of a military presence in a disputed territory that does not involve violent use of force. The ICJ did not address this question in the Costa Rica v Nicaragua judgment nor in the Cameroon v Nigeria judgment. Judge Robinson referred to the Corfu Channel judgment as relevant jurisprudence in his separate opinion in the Costa Rica v Nicaragua judgment, but while the ICJ found that the British naval activities in Albanian waters violated Albanian sovereignty, it did not directly pronounce upon whether there had been a violation of Article 2(4) of the UN Charter.Footnote 8 Randelzhofer and Dörr discussed the notion of ‘force’ under Article 2(4) in their commentary on the UN Charter and said it ‘does not cover any possible kind of force, but is, according to the correct and prevailing view, limited to armed force’. However, they did not address the issue of non-violent use of force in their commentary.Footnote 9 In this article, considering the apparent gap in jurisprudence and the major literatures, the legality of the non-violent establishment of a military presence in a disputed territory under Article 2(4) will be examined.
In addition, as Tomuschat points out in his commentary, Article 2(3) ‘occupies a pivotal position within a world order whose hallmark is the ban on force and coercion’.Footnote 10 Although Costa Rica did not raise the issue of legality under Article 2(3) of the UN Charter in its submission in the Costa Rica v Nicaragua case, as the obligation to settle disputes peacefully reinforces the prohibition of the use of force in promoting international peace and security, the legality of the non-violent establishment of a military presence in a disputed territory under Article 2(3) will also be examined.
The interpretation of Articles 2(3) and (4) of the UN Charter in this article will be based on the framework of Article 31 of the Vienna Convention on the Law of Treaties (VCLT). In applying that framework, relevant GA resolutions relating to the interpretation of Articles 2(3) and (4) of the UN Charter will be examined as possible subsequent agreements or practice under Article 31(3) of the VCLT.Footnote 11 Considering the importance of the views of the ICJ as the principal judicial organ of the United Nations regarding the interpretation of the UN Charter, its Advisory Opinion on the Wall case will also be examined. Before examining the interpretation of Articles 2(3) and (4) based on the framework of Article 31 of the VCLT, the relevance and applicability of Articles 2(3) and (4) to the establishment of a military presence in a disputed territory will be ascertained through reviewing several cases referred to third party dispute settlement procedures, which directly or indirectly relate to the establishment of a military presence in a disputed territory.
II. RELEVANT CASES
A. Cases Directly or Indirectly Relating to Article 2(4)
1. Eritrea-Ethiopia Claims Commission
Relying on the language of threat or use of force ‘against the territorial integrity’ in Article 2(4) of the UN Charter, a State using force in an area where it claims sovereignty might argue that its use of force is not ‘against the territorial integrity’ and, therefore, falls outside the scope of Article 2(4). However, the 2005 Partial Award of the Eritrea-Ethiopia Claims Commission recognized that the existence of territorial disputes does not preclude the applicability of the prohibition of the threat or use of force. It noted: ‘… border disputes between States are so frequent that any exception to the prohibition of the threat or use of force for territory that is allegedly occupied unlawfully would create a large and dangerous hole in a fundamental rule of international law’.Footnote 12 The Eritrea-Ethiopia Claims Commission found that Eritrea violated Article 2(4) of the UN Charter by attacking and occupying in 1998 the town of Badme, whose sovereignty was claimed by Eritrea but which the Commission found was under ‘peaceful administration’ by Ethiopia at the time.Footnote 13
2. Guyana v Suriname
In the Guyana v Suriname case, Suriname sent a naval vessel to a maritime area disputed with Guyana. The Arbitral Tribunal established under Annex VII of the UN Convention on the Law of the Sea (UNCLOS) found in its 2007 award that: ‘The expulsion from the disputed area of the CGX oil rig and drill ship C. E. Thornton by Suriname on 3 June 2000 constituted a threat of the use of force in breach of the Convention, the UN Charter, and general international law.’Footnote 14
This Award dealt with a deployment of armed forces to a disputed maritime area. Therefore, it did not directly concern military activities in a disputed territory. However, confirming the view of the 2005 Partial Award of Eritrea-Ethiopia Claims Commission, the Arbitral Tribunal found that UNCLOS makes no mention of the incompatibility of claims relating to the use of force in a disputed area and a claim or maritime delimitation of that area.Footnote 15
3. Costa Rica v Nicaragua and Cameroon v Nigeria
As quoted above, the ICJ avoided pronouncing on the interpretation of Article 2(4) in the Costa Rica v Nicaragua case based on its own precedent in the Cameroon v Nigeria case. In the Cameroon v Nigeria judgment, the ICJ avoided addressing the issue of Nigeria's responsibility to Cameroon as a result of Nigeria's occupation of territory that was determined to be Cameroon's territory. It did so because it found that its own judgment and the evacuation of the Cameroonian territory occupied by Nigeria sufficiently addressed the injury suffered by Cameroon.Footnote 16 These judgments avoided pronouncing on the interpretation of Article 2(4) not because they denied that there had been a violation of Article 2(4) by the establishment of a military presence in the disputed territories, but because their judgments and the evacuation based on them sufficiently addressed possible claims to have suffered injury.
4. South China Sea
In the South China Sea various coastal States claim land and maritime areas. China and other claimants have constructed facilities on maritime features. In 2002, the Declaration on the Conduct of Parties in the South China Sea (DOC) was signed by all the ASEAN members and China. In the DOC, the parties concerned undertook to resolve their territorial and jurisdictional disputes by peaceful means, without resorting to the threat or use of force.Footnote 17 The claimants in the South China Sea, therefore, seem to recognize the existence of territorial disputes and the applicability of the prohibition of use of force and the obligation to settle disputes peacefully.
On 22 November 2015, the East Asia Summit, in which all the ASEAN members, China, the US and Japan participated, issued a Chairman's Statement. In the section titled ‘South China Sea’, participating States welcomed assurances given by China as expressed by President Xi Jinping during his visit to the US that China does not intend to pursue militarization in the South China Sea, and underscored the commitment of ASEAN member States and China not to resort to the threat or use of force and to resolve their differences and disputes through peaceful means, in accordance with international law, including UNCLOS.Footnote 18 This statement also seems to confirm the applicability of the prohibition of the use of force and the obligation to settle disputes peacefully to the territorial disputes over the islands in the South China Sea, while cautioning against ‘militarization’ in the South China Sea.
There were exchanges of fire in the South China Sea in the past, including an incident in 1988 between China and Vietnam near Johnson Reef, but China did not fire weapons during its recent large-scale reclamation and construction activities in the South China Sea which took place at the same time as the arbitration under UNCLOS. Because of China's declaration under Article 298 of UNCLOS, the Philippines v PRC arbitration could not directly deal with issues relating to military activities. Therefore, the Philippines did not raise the issue of the use of force in the arbitration. The only reference to Chinese military activities in the award seems to be the characterization of the stand-off at Second Thomas Shoal as a ‘military situation’, which led to the denial of the jurisdiction over the incident by the arbitral tribunal.Footnote 19
B. Cases Directly or Indirectly Relating to Article 2(3)
1. Philippines v PRC
In the Philippines v PRC arbitration, the Philippines argued that China's dredging and construction activities during the arbitral proceedings aggravated and extended the disputes, and the tribunal declared that China had breached its obligations pursuant to Article 279 and other provisions of UNCLOS.Footnote 20 Article 279 provides:
States Parties shall settle any dispute between them concerning the interpretation or application of this Convention by peaceful means in accordance with Article 2, paragraph 3, of the Charter of the United Nations and, to this end, shall seek a solution by the means indicated in Article 33, paragraph 1, of the Charter.
In its reasoning, the arbitral tribunal acknowledged: ‘the duty on parties engaged in a dispute settlement procedure to refrain from aggravating or extending the dispute or disputes at issue during the pendency of the settlement process … exists independently of any order from a court or tribunal to refrain from aggravating or extending the dispute and stems from the purpose of dispute settlement and the status of the States in question as parties in such proceeding’.Footnote 21
In cases involving territorial disputes before the ICJ, provisional measure orders have been issued to stop the sending of military and other forces to disputed territories. Through reference to Article 279 of UNCLOS, the Philippines v PRC award indirectly clarified the existence of the obligation under Article 2(3) of the UN Charter to settle disputes peacefully independently of provisional measure orders. Although it did not equate the obligation imposed by the provisional measure orders not to aggravate or extend disputes with the obligation under Article 2(3) of the UN Charter, it at least indicated the relevance of such provisional measure orders to the obligation under Article 2(3) of the UN Charter.
2. Cambodia v Thailand
On 18 July 2011, the ICJ ordered provisional measures in the case of Request for Interpretation of the Judgment of 15 June 1962 in the Case concerning the Temple of Preah Vihear (Cambodia v Thailand). The order states: ‘(1) Both Parties shall immediately withdraw their military personnel currently present in the provisional demilitarized zone, as defined in paragraph 62 of the present Order, and refrain from any military presence within that zone and from any armed activity directed at that zone.’Footnote 22
In the second paragraph of the Dispositive of the 1962 judgment, the ICJ declared: ‘Thailand is under an obligation to withdraw any military or police forces, or other guards or keepers, stationed by her at the Temple, or in its vicinity on Cambodian territory’,Footnote 23 but there remained a dispute between Cambodia and Thailand over the meaning of the area in the temple's vicinity. Therefore, the ICJ designated a zone including the disputed territory as a demilitarized zone.
In the provisional measure order in 2011, the ICJ ordered both parties to immediately withdraw their military personnel from the provisional demilitarized zone and to refrain from any action that might aggravate or extend the dispute before the ICJ or make it more difficult to resolve.Footnote 24
Article 41(1) of the ICJ Statute provides: ‘The Court shall have the power to indicate, if it considers that circumstances so require, any provisional measures which ought to be taken to preserve the respective rights of either party.’ Therefore, the ICJ's order to the parties to withdraw their military personnel from the disputed territory was taken in order to preserve the rights of the parties. Since the ICJ has the power to indicate provisional measures under Article 41(1) of the statute, there was no need for the ICJ to examine the violation of Article 2(3) of the UN Charter when ordering the stopping of the deployment of military personnel to the disputed territory. On the other hand, considering the connection between the provisional measures and the obligation under Article 2(3) indicated in the Philippines v PRC award, the fact that the ICJ ordered the parties not to deploy military personnel to the disputed territory in this case can be interpreted as indicating the ICJ's recognition that the deployment of military personnel to the disputed territory would be inconsistent with the obligation of the parties to settle their territorial dispute peacefully. The reference to the obligation under Article 2(3) in paragraph 63 of the 2011 provisional measure order seems to support the relevance of the obligation under Article 2(3) to the order to withdraw military personnel from the disputed land territory.Footnote 25
3. Costa Rica v Nicaragua
On 8 March 2011, the ICJ ordered provisional measures in the Costa Rica v Nicaragua case. The ICJ ordered: ‘Each Party shall refrain from sending to, or maintaining in the disputed territory, including the caño, any personnel, whether civilian, police or security.’Footnote 26 As quoted above, in the judgment of 16 December 2015 on this case, the ICJ found: ‘by excavating two caños in 2013 and establishing a military presence in the disputed territory, Nicaragua has breached the obligations incumbent upon it under the Order indicating provisional measures issued by the ICJ on 8 March 2011’.Footnote 27
Considering the connection between provisional measure orders and the obligation under Article 2(3) of the UN Charter, this judgment can also be interpreted as indicating that Nicaragua's establishment of a military presence in the disputed territory was inconsistent with the obligation to settle disputes peacefully under Article 2(3).
III. POSSIBLE INTERPRETATIONs OF ARTICLEs 2(3) AND (4)
The cases quoted above seem to confirm the applicability of Article 2(3) and (4) of the UN Charter to the claimants’ activities in disputed territories, and these provisional measure orders stopping the sending of military personnel to disputed territories seem to indicate the existence of a similar obligation under Article 2(3). However, Eritrea's deployment of force to Badme in the Eritrea-Ethiopia case involved the violent use of force, and other cases discussed above did not directly address the legality of establishing a military presence in disputed land territories under Article 2(3) and (4). Therefore, these cases do not provide a direct answer to the question of the legality of the establishment of a military presence in a disputed territory not involving the violent use of force under Article 2(3) and (4) of the UN Charter.
A. Article 2(3)
Article 2(3) reads: ‘All Members shall settle their international disputes by peaceful means in such a manner that international peace and security, and justice, are not endangered.’ According to Article 31(1) of the VCLT, a treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. The first paragraph of the Preamble of the UN Charter reads: ‘We the peoples of the United Nations determined to save succeeding generations from the scourge of war, which twice in our life time has brought untold sorrow to mankind.’ Article 1 of the UN Charter provides:
The Purposes of the United Nations are:
1. To maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace;
While these provisions provide important context, object and purpose for Article 2(3), to clarify the legality of the establishment of a military presence in disputed territories under Article 2(3), subsequent agreements and practices under Article 31(3) of the VCLT should also be taken into account.
1. The Friendly Relations Declaration
Article 31(3) of the VCLT provides that ‘any subsequent agreement between the parties regarding the interpretation of the treaty or the application of its provision’ and ‘any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation’ shall be taken into account. One of the most important subsequent agreements or practice between the parties to the UN Charter regarding its interpretation is probably the Friendly Relations Declaration.Footnote 28 It sets out two aspects of the obligations under Article 2(3), namely, the obligation to seek the settlement of disputes by peaceful means and the obligation to refrain from any action that may aggravate the disputes. The paragraphs of the Friendly Relations Declaration relating to the two aspects of the obligations under Article 2(3) read:
The parties to a dispute have the duty, in the event of failure to reach a solution by any one of the above peaceful means, to continue to seek a settlement of the dispute by other peaceful means agreed upon by them.
States parties to an international dispute, as well as other States shall refrain from any action which may aggravate the Situation so as to endanger the maintenance of international peace and security, and shall act in accordance with the purposes and principles of the United Nations.
2. The Manila Declaration
Another important subsequent agreement or practice was embodied in the ‘Manila Declaration on the Peaceful Settlement of Disputes between States’ (Manila Declaration) of 1982 (UNGA Res/37/10).Footnote 29 The preamble of the Manila Declaration reaffirmed ‘the need to exert utmost efforts in order to settle any conflicts and disputes between States exclusively by peaceful means and to avoid any military action and hostilities’. This preamble seems to further clarify the two aspects of the obligation under Article 2(3) by stating that States not only have an obligation to do their utmost to settle any conflicts and disputes arising between themselves and other States exclusively by peaceful means but they also have an obligation to avoid any military action and hostilities. Operative paragraph 2 of the Manila Declaration further clarifies the content of these obligations: ‘Every State shall settle its international dispute exclusively by peaceful means in such a manner that international peace and security, and justice, are not endangered.’
If a State establishes a military presence by building camps and facilities used or controlled by the military to change the status quo in a disputed territory, it would not be regarded as a ‘peaceful’ means of settling the territorial dispute. Therefore, considering the language of the Manila Declaration, such behaviour would violate Article 2(3), which requires States to settle their international disputes ‘exclusively’ by peaceful means. This understanding also seems to be consistent with the ICJ's provisional measure orders prohibiting the deployment of military personnel to disputed territories.
On the other hand, this does not mean that any action involving the military in a disputed territory violates Article 2(3). If a State started to exercise control over a territory without facing any protest from other States and, after the establishment of control over the territory, another State starts to make a claim regarding the sovereignty of the territory and attempts to challenge the existing control by sending armed forces, the State that has been controlling the territory should be allowed to respond with proportionate means involving the military, if necessary. However, as the precise conditions for the lawful response in this context would require extensive analysis, it goes beyond the scope of this article.
B. Article 2(4)
Article 2(4) reads: ‘All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.’ While the Preamble and Article 1(1) of the UN Charter provide important context, object and purpose for Article 2(4), to clarify the legality of the establishment of a military presence in disputed territories under Article 2(4), subsequent agreements and practice under Article 31(3) of the VCLT should be taken into account.
1. The Friendly Relations Declaration
As a subsequent agreement or practice, the Friendly Relations Declaration contains several paragraphs relating to the obligation under Article 2(4) that seem particularly relevant to the establishment of a military presence in a disputed territory. These paragraphs of the Friendly Relations Declaration read:
Every State has the duty to refrain in its international relations from the threat or use of force against the territorial integrity or political independence of any State, or in any other manner inconsistent with the purposes of the United Nations. Such a threat or use of force constitutes a violation of international law and the Charter of the United Nations and shall never be employed as a means of settling international issues. …
Every State has the duty to refrain from the threat or use of force to violate the existing international boundaries of another State or as a means of solving international disputes, including territorial disputes and problems concerning frontiers of States.
The Friendly Relations Declaration also emphasizes that ‘No territorial acquisition resulting from the threat or use of force shall be recognized as legal’, and the Security Council and the General Assembly have repeatedly affirmed the inadmissibility of the acquisition of territory by force.Footnote 30
The GA resolution 3314(XXIX) on the Definition of Aggression refers to actions that do not necessarily involve the violent use of force such as ‘the use of armed forces of one State which are within the territory of another State with the agreement of the receiving State, in contravention of the conditions provided for in the agreement or any extension of their presence in such territory beyond the termination of the agreement’.Footnote 31 ‘The blockade of the ports or coasts of a State by the armed force of another State’ does not necessarily involve the violent use of force either. This resolution, therefore, seems to support the view that the prohibition of the use of force under Article 2(4) of the UN Charter is not necessarily limited to the violent use of force.
2. The Advisory Opinion on the Wall case
If the prohibition on the use of force under Article 2(4) applies to the non-violent use of force, what is the element other than violence that makes military activities in a disputed territory an unlawful use of force under Article 2(4)?
The ICJ examined the principle of the inadmissibility of acquisition of territory by force in its Advisory Opinion concerning ‘Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory’. The issue of sovereignty in the Occupied Palestinian Territory is not settled.Footnote 32 In the Advisory Opinion, the ICJ quoted Security Council resolutions 242(1967) and 298(1971) which referred to the inadmissibility of the acquisition of territory by war or military conquest.Footnote 33 The ICJ, quoting Article 2(4) and the Friendly Relations Declaration, recognized the inadmissibility of the acquisition of territory by force as a principle regarding the use of force incorporated in the UN Charter and examined the legality of the wall in the context of the inadmissibility of the acquisition of territory by force and the principle of self-determination.Footnote 34 Paragraph 121 of the opinion reads: ‘The Court considers that the construction of the wall and its associated regime create a “fait accompli” on the ground that could well become permanent, in which case, and notwithstanding the formal characterization of the wall by Israel, it would be tantamount to de facto annexation.’
This seems to be applying the principle of the inadmissibility of the acquisition of territory by force to the Israeli construction of the wall in the Occupied Palestinian Territory. Israel occupied the Occupied Palestinian Territory as a result of the Six-Day War in 1967 and has since continued its occupation. The Israeli construction of the wall in question consisted of various facilities and installations, including a fence, a ditch, a road and a concrete wall.Footnote 35 The ICJ's Advisory Opinion seems to apply the principle of the inadmissibility of acquisition of territory by force to the construction of the wall itself without referring to the violent use of force in 1967 by Israel. Therefore, the ICJ seems to consider that the construction of the wall amounts to the acquisition of territory by force prohibited under Article 2(4) because it creates a ‘fait accompli’ and not because Israel took control of the territory through the violent use of force. This creation of a ‘fait accompli’ seems to have played an important element in the ICJ's opinion in the Wall case when applying the principle of the inadmissibility of the acquisition of territory by force. To create a ‘fait accompli’ some element of force is needed to deter other claimant(s) from interfering with the control of the territory, and this deterring effect seems to be the core element of the unlawful use of force under Article 2(4).
3. ‘Coercion’ as a key element
Judge Robinson pointed out the importance of the coercive element in the prohibition of the use of force in his separate opinion on the Costa Rica v Nicaragua case.Footnote 36 Dörr, who was quoted by Judge Robinson, emphasizes: ‘The essential feature which characterizes the prohibition of the use of force is the application of military force as a means of coercion.’Footnote 37
Articles 51 and 52 of the VCLT use the term ‘coercion’ when considering the causes of invalidity of treaties. Article 51 relates to the coercion of a representative of a State, but Article 52 relates to the coercion of a State itself. Article 18 of the ILC's Draft Articles on Responsibility of States for International Wrongful Acts (Draft Articles) also uses the term ‘coercion’ in the context of the rules regarding the responsibility of a coercing State in connection with the act of the coerced State. While the commentary on Article 52 of the VCLT simply equates the notion of coercion with a threat or use of force in violation of the principles of the UN Charter, the commentary on Article 18 of the Draft Articles states that coercion for the purpose of this article has the same essential character as force majeure under Article 23 of the Draft Articles.Footnote 38 Article 23 and its commentary explain the elements constituting a situation of force majeure and refer to the effect of making it ‘materially impossible’ in the circumstances to perform the obligation.Footnote 39 Article 18 of the Draft Articles concerns a situation where a State breaches an international obligation due to coercion, but coercion is not limited to such a situation. In the context of military activities by a claimant to change the status quo in a disputed territory, the effect of making it ‘materially impossible’ for the other claimants to restore the status quo ante seems to be the essence of coercion.
The establishment of a military presence in a disputed territory by a claimant is likely to create a ‘fait accompli’ by making it materially impossible for other claimants to restore the status quo ante. The construction of the wall in the Wall case probably had the effect of making it materially impossible for the Palestinians to restore the status quo ante in the territory protected by the wall without risking human injury or damage to property, and thus it created a ‘fait accompli’. Therefore, making it materially impossible for other claimants to restore the status quo ante in the disputed territories without risking human injury or damage to property seems to be the key element in making the establishment of a military presence in a disputed territory constitute the unlawful acquisition of a territory by force and a violation of Article 2(4). This element can probably be called ‘coercion’.Footnote 40
If coercion is the key element constituting the unlawful use of force under Article 2(4), what kind of military presence in a disputed territory is likely to have a coercive effect? It would naturally depend upon the situation and context, but, for example, the stronger the weapons deployed are, the likelier it would be that the military presence has the effect of making it materially impossible for other claimants to restore the status quo ante without risking human injury or damage to property.Footnote 41 Furthermore, the scale of the activities protected by the military presence also seems to be relevant.Footnote 42 The larger the scale of the activities protected by the military presence in the disputed territory, the likelier it is that the establishment of a military presence makes it materially impossible for other claimants to restore the status quo ante without risking human injury or damage to property.
In addition, in the Cameroon v Nigeria case and the Costa Rica v Nicaragua case the parties accepted the jurisdiction of the ICJ on the basis of declarations under Article 36(2) of the ICJ Statute and the Pact of Bogota. Their acceptance of the ICJ's jurisdiction might have mitigated the coercive effect of the Nigerian and Nicaraguan actions to some extent. If parties to a territorial dispute accept the ICJ's jurisdiction over that dispute, the dispute itself can be resolved on the basis of international law. Therefore, the acceptance of a peaceful means of settlement based on international law might mitigate the coercive effect.
Based on the foregoing analysis, to constitute an unlawful use of force under Article 2(4), a military action in a disputed territory does not have to be violent but should involve coercion which makes it materially impossible for other claimants to restore the status quo ante in the disputed territory without risking human injury or damage to property.Footnote 43 The factors mentioned above, including the strength of the weapons deployed, and the scale of the activities protected by the military presence would contribute to the coerciveness. In addition, possibly, the acceptance of a peaceful means of settlement based on international law might mitigate the coercive effect.
IV. CONCLUSIONS
If a State establishes a military presence by building camps and facilities used or controlled by its military in order to change the status quo in a disputed territory, this would not be regarded as a ‘peaceful’ means of settling a dispute. Therefore, considering the language of the Manila Declaration, such behaviour would violate Article 2(3), which requires States to settle their international disputes ‘exclusively’ by peaceful means.
Furthermore, to constitute an unlawful use of force under Article 2(4), the establishment of a military presence by a claimant in a disputed territory does not have to be violent but should involve coercion which makes it materially impossible for other claimants to restore the status quo ante in the disputed territory without risking human injury or damage to property.
These conclusions should hopefully discourage States from resorting to military measures to resolve international disputes in their favour and thus contribute to the maintenance of international peace and security, which is the most important purpose of the UN. These conclusions should also contribute to the ‘rule of law’ in the international community, or the rule-based international order, by encouraging the settlement of disputes based on international law.
