“The primary factor in the decision to litigate must be the availability of this option in the first place.” ^{Footnote 1} This unassailable truth is immediately followed by a further, compelling question: why do states decide to litigate? The wish to answer this question marks the return of Natalie Klein to the topic of international dispute settlement, after her excellent book on the mechanism for settling disputes in the 1982 UN Convention on the Law of the Sea (UNCLOS). ^{Footnote 2}

As it is put by Klein, “the field is ripe for empirical research” and rightly so — the last seventy years have witnessed a sharp increase in both the number of international judicial bodies and the number of international decisions rendered. After the establishment of the International Court of Justice (ICJ), history did not have to wait long to see new courts and tribunals instituted, such as the Inter-American Court of Human Rights, ^{Footnote 3} the European Court of Human Rights, ^{Footnote 4} the International Centre for the Settlement of Investment Disputes (ICSID), ^{Footnote 5} the International Tribunal for the Law of the Sea (ITLOS), ^{Footnote 6} as well as others. This gradual increase received a sudden boost in the 1990s with the institution of international criminal tribunals, such as the ones for the former Yugoslavia and for Rwanda, and the permanent International Criminal Court. ^{Footnote 7} A major development was also the creation in 1995 of the dispute settlement system under the Marrakesh Agreement Establishing the World Trade Organization, which established the panels and Appellate Body of the World Trade Organization (WTO) ^{Footnote 8} — the busiest international judicial organ today, with a caseload surpassing that of the ICJ, ITLOS, and the international criminal tribunals combined. In addition, one must not forget arbitration, which is the oldest method of peacefully settling international disputes. Today, arbitration is particularly frequent in the field of investment disputes, where public and private international law blend together to give rise to a peculiar, hybrid arbitral process.

This overview of today’s international courts and tribunals shows one aspect, probably one of the most striking, of modern international law: States appear to be fond of international litigation. However, this plethora of judicial organs, whose primary clientele are states themselves, cannot be justified. There may be the temptation to dismiss the question posed in Litigating International Law Disputes by simply considering that states prefer litigation than resolving their differences by recourse to armed force, as was customary for centuries; however, as Klein and the other contributors show, the question is much more complex and requires a more analytical approach.

The editor of Litigating International Law Disputes adopted this analytical approach by dividing the opus into three parts, which are each dedicated to a macro-aspect of the topic. The first part sets the scene by dealing with the place of international litigation in the settlement of international disputes. The second part examines selected regional and national perspectives on international litigation. The third part leads the reader through various fields of international law, from the law of armed conflict, to investment law, to the law of the sea, addressing, in each case, the reasons that induce states to litigate an international dispute in light of the peculiarities of the field in question. The twenty chapters of the book have been written, in the reviewer’s opinion, by a successful team of scholars, practitioners, and government officials, under the careful direction of Klein.

The opening chapter of the book was entrusted to John Merrills and discusses questions about the role of precedent in international litigation as well as the system of the sources of international law as codified in Article 38(1) of the Statute of the International Court of Justice. ^{Footnote 9} Certainly, as Merrills points out, litigation is not suitable for all kinds of disputes and should not be conceived as a panacea. Merrills also introduces one of the book’s underlying themes: the politicization of international litigation. According to him, however, political disputes can be led back into the precinct of the law, particularly through the work of international judges (a striking example is US Diplomatic and Consular Staff in Tehran). ^{Footnote 10} Merrills’s analysis is somewhat complemented by that of Shirley Scott, who scrutinizes the main reasons leading to the decision to litigate at the international level. Scott divides such reasons between short-term and long-term benefits, with the caveat that the core issue for any state is the preservation of its sovereign powers. Electa una via non datur recursus ad alteram — one can say by approximation that once a state has seized a judicial organ, international justice will take it from there. In light of this, sometimes states prefer to keep their options open by resorting to domestic courts to settle an international dispute. However, as Christopher Ward shows us, there may be considerable obstacles, from questions of justiciability, to the so-called act of state doctrine, to, more simply, the unpredictability of national judges in deciding disputes that often are not within their comfort zone. ^{Footnote 11} Ward labels the US experience as peculiar, due to the recent revival of the Alien Tort Statute (ATS), which allows for universal jurisdiction with respect to tort claims in breach of the law of nations. ^{Footnote 12} However, at the time this chapter was written, the United States Supreme Court had not yet rendered its judgment in Kiobel v Royal Dutch Petroleum, which significantly reduced the scope of the ATS and the jurisdictional reach of US courts. ^{Footnote 13}

The second part of the book focuses on national and regional experiences concerning international litigation: the authors analyze the perspectives of Australia (Henry Burmester), Latin America (Ximena Fuentes), the United States (Mark Feldman), Western Europe (Michael Wood), Asia (Rodman Bundy), and Africa (Makane Mbengue). The underlying idea of these chapters is that in each region states have, to different extents, contributed to the development of international litigation. The only exception is that of Africa, where, by admission of Mbengue himself, there has been a tendency, especially since the South West Africa Cases, towards regionalization and delegalization of international disputes. ^{Footnote 14} On the one hand, African states appear to prefer regional means of dispute settlement to international bodies such as the ICJ, while, on the other hand, the political nature of many controversies between African countries points towards a political, rather than a legal, means of dispute settlement. As to the other regional and national experiences, they share various points in common: a relatively wide acceptance of the optional clause providing for compulsory jurisdiction of the ICJ, a noteworthy participation in the UNCLOS dispute settlement mechanism, and a high number of international claims filed (especially by Latin American countries). The only two countries deserving a mention of their own are the United States and China. Despite being prominent members of the elite P5 club, they are generally cautious with respect to international litigation. China has never been a party to any case before standing international tribunals ^{Footnote 15} and is currently declining to appear in the Annex VII arbitration concerning The Republic of the Philippines v The People’s Republic of China. ^{Footnote 16} As for the United States, after the preliminary objections in Military and Paramilitary Activities in and against Nicaragua, ^{Footnote 17} it withdrew its acceptance of the optional clause and has appeared reluctantly before the ICJ. Its mistrust towards international litigation was strengthened by the outcome of cases such as Oil Platforms. ^{Footnote 18} Today, the United States is mainly active before the WTO.

The third part of the book opens with two chapters dedicated to boundary disputes. Lea Brilmayer and Adele Faure analyze territorial frontier questions, adopting a perspective that, although based in law, is deeply influenced by political science. On the other hand, Coalter Lathrop discusses maritime boundary litigation, whose main features are the shift to ante hoc consent (especially under Article 287 of UNCLOS and the optional clause) and the pursuit of negotiation in parallel to litigation. Lathrop’s analysis is immediately followed by M.D. Saiful Karim’s overview of litigation under UNCLOS. This overview points out an increasing interest in litigating under UNCLOS, due to compulsory jurisdiction under Part XV as well as to the bearing of extra-legal factors, such as political and economic considerations. Tim Stephens, in dealing with environmental disputes, highlights the recent surge in litigation in that field. Since Gabčíkovo-Nagymaros Project, ^{Footnote 19} states have litigated environmental disputes more frequently than in the past, and more cases of this sort can be expected in the future. ^{Footnote 20}

The political question underlying the decision to start litigation features prominently in the chapters dedicated to armed conflict (Christine Gray and John Crook) and to human rights (Ivan Shearer). In both cases, political concerns permeate states’ considerations when weighing their dispute settlement options. In addition, there is a tendency to avoid litigation in the context of armed conflict, due to obstacles such as evidence gathering and complex jurisdictional challenges. Moreover, international human rights law lacks a truly international dispute settlement system, despite the existence of important international instruments (such as the International Covenant on Civil and Political Rights and the International Convention on the Elimination of All Forms of Racial Discrimination), with states preferring to rely on regional mechanisms (such as the framework of the Convention for the Protection of Human Rights and Fundamental Freedoms). ^{Footnote 21}

The domain of international economic law is left to the pages of M. Rafiqul Islam on the WTO and of Chester Brown on international investments. Islam underscores the characteristics that make the WTO an attractive dispute settlement system: expeditiousness, confidentiality, and effective enforcement. At the same time, however, the author avows that a better balance must be sought between developed and developing countries, as the latter, though receiving special and differential treatment in many instances, still lack the political and economic standing to pursue the effective enforcement of WTO obligations. With respect to investment law, Brown shows that multiple means of dispute settlement are available: ICSID and ad hoc arbitration; domestic litigation; conciliation; as well as negotiation. The surge in investment litigation has determined the development of both procedural standards (concerning consent to jurisdiction) and substantive standards (national treatment, most favoured nation, full protection and security, and so on), while giving rise to genuine concerns relating to the possibility that private persons could challenge measures adopted by sovereign entities. In other words, international investment litigation defies the traditional sovereignty of the state, with consequences that are for future jurists to evaluate. Investment claims can also be pursued by way of diplomatic protection, ^{Footnote 22} as Klein reminds us. However, the realm of diplomatic protection extends well beyond investment law to human rights, ^{Footnote 23} consular assistance, ^{Footnote 24} and other areas. Diplomatic protection was used more widely in the past, due to more effective and expeditious means being available today; additionally, the nationality of claims and the exhaustion of local remedies make diplomatic protection a complicated means of dispute settlement.

Cesare Romano wrote the concluding chapter on future developments. Quoting Niels Bohr, Romano recalls that “prediction is very difficult, especially about the future.” ^{Footnote 25} Nonetheless, he proceeds to foreshadow that no brand new judicial organs will be created in the near future, while there will be an increase in the caseload of the existing ones. The reader is then left not with an answer, but with a question. Understanding why states litigate is but the starting point and leads to a new issue: why should states litigate?

One can hope that the collective effort put into Litigating International Law Disputes will be repeated, with a focus on the question that Romano leaves open. Klein’s edited collection constitutes, in the reviewer’s opinion, a valuable addition to the literature on the settlement of international disputes. Despite many issues being inherently political, the book successfully ties them to the law, without losing sight of the aim of clarifying why states litigate at the international level. The reviewer recommends Natalie Klein’s book to all those who already have a grasp of international dispute settlement. While the beginner could find that the book does not explain the basics of international litigation (which is not its intent), the initiated reader will surely find many precious insights of both an academic and practical nature.