Comparative approaches to international courts and tribunals have grown in number, kind, and popularity in recent years. As multiple international adjudicative bodies with overlapping jurisdiction wrestle with similar substantive matters, practitioners and scholars have evaluated how the law has converged or diverged in areas as wide-ranging as maritime boundary delimitation, genocide, and international investment. Comparisons of international courts to better conceptualize and understand legitimacy and effectiveness in a fragmented environment are more recent additions.Footnote ¹ Cameron A. Miles's Provisional Measures is part of a procedural turn in the literature on comparative approaches to international courts and tribunals, building, for example, on Chester Brown's A Common Law of International Adjudication.Footnote ² This literature also includes the recently launched Max Planck Encyclopedia of International Procedural Law.Footnote ³

A barrister based in London who represents clients before international courts and tribunals, Miles seeks to explore the extent to which a unified approach to provisional measures exists across international courts and tribunals. He defines provisional measures, also called “interim measures,” “interim protection,” and “interim measures of protection,” as “orders requiring the parties to a dispute to do (or not do) something so as to preserve the subject matter of the dispute pending resolution” (p. 1). The book's thesis is that the practice of international courts and tribunals has converged such that a uniform approach to awarding provisional measures now exists (p. 5). In testing his thesis, Miles engages in a comprehensive and thorough study of the decisions of the International Court of Justice (ICJ), the International Tribunal for the Law of the Sea (ITLOS), Annex VII tribunals under the United Nations Convention on the Law of the Sea's (UNCLOS) Part XV, ad hoc interstate arbitral tribunals, and investor-state arbitration tribunals, such as the International Centre for Settlement of Investment Disputes (ICSID) and the Iran-U.S. Claims Tribunal.

The book consists of three parts, divided into ten chapters. Part I introduces the historical origins of provisional measures, the adjudicative bodies covered in the study, and relevant aspects of constituent instruments and rules of procedure. Miles asserts that the jurisprudence from the waning days of the Permanent Court of International Justice (PCIJ) draws from a wider tradition of provisional measures in international and municipal law. As regards international influences, similar to Shabtai Rosenne's work on the topic,Footnote ⁴ Miles refers to codification projects based in Europe at the turn of the twentieth century, the jurisprudence of the now long-defunct Central American Court of Justice, strongly influenced by the United States, as well as the Bryan treaties (a series of treaties for advancing peace between the United States and several other states dating to the early twentieth century), and awards of mixed arbitral tribunals. Municipal law analysis is limited to Greco-Roman, canon, common, and civil law traditions, as found in the United Kingdom, the United States, France, Germany, and Switzerland. Miles justifies his choice to look closely at the latter three countries’ law, in part, because Swiss PCIJ President Max Huber informally corresponded with his French and Dutch colleagues when receiving and deciding the first PCIJ request for provisional measures in the Sino-Belgian Treaty case.Footnote ⁵

Miles's account of history suggests that the law of provisional measures in place at the birth of the ICJ was primarily, if not exclusively, Anglo-European in nature, and primarily reflective of the civil law tradition. While the Anglo and European traditions undoubtedly played a pivotal role in the development of the law of provisional measures during this period, where “civilized” state practice was of fundamental importance, the absence of any discussion of municipal law from other parts of the world, or of international dispute resolution not heavily influenced by the Anglo-European tradition, is striking. With virtually no information about these other legal traditions, it is difficult to assess whether they too may have played a role in the development of provisional measures. Assuming Miles's historical account is accurate, particularly considering geopolitics at the time, it strongly supports the “Third World Approaches to International Law” view that what we call “international law” is, in fact, a Northern and Western construct, at least with respect to provisional measures.

Part II identifies and explains the functioning of and preconditions for provisional measures before the international courts and tribunals included in the study. Chapters 4 through 7 address the power to issue provisional measures, the purposes of provisional measures, and the content and enforcement of provisional measures, and they describe the five preconditions for the ordering of provisional measures. These are: (1) prima facie jurisdiction; (2) a link between the measures requested and the rights to be adjudicated in the final judgment; (3) oversight of some kind of the merits through a determination of plausibility of the rights at issue, or prima facie review; (4) risk of irreparable prejudice; and (5) urgency. Miles describes the various adjudicative bodies’ approach to each of these preconditions in a thorough and detailed manner, and he draws conclusions about where common practice exists and where it diverges.

These chapters are of great use to scholars and practitioners seeking to understand the provisional measures practice of each of the adjudicative bodies surveyed. A one-stop shop for the key provisions of relevant constituent instruments and rules of procedure, the chapters identify and analyze leading cases involving interim relief for the courts and tribunals included in the study. The footnotes, too, provide a comprehensive list of key secondary sources on interim relief. Part II goes beyond a mere survey of existing practice, providing context and historical background for each of the topics addressed and situating them within the existing literature. Of particular note is the detailed explanation and analysis of the LaGrand case and its impact.Footnote ⁶ This watershed ICJ case resolved a longstanding debate about the binding nature of interim relief orders, although, as Miles thoughtfully elaborates, it left many unresolved questions in its wake, particularly involving state responsibility. Among other helpful additions to the literature are a compilation of previous interim relief measures ordered, and discussion and analysis of issues to be addressed in crafting a request for provisional measures or preparing an order granting them. A practitioner or scholar requiring a deep and thoughtful overview of the law on interim relief would find this a worthy and useful resource to have on her or his bookshelf.

While Miles shows convergence in provisional measures practice among the courts and tribunals surveyed, the extent to which he demonstrates a generally uniform approach among international courts and tribunals as a group is less clear. His thesis, as previously stated, is that the practice of interim relief has converged such that a generally uniform approach now exists. Yet Miles has explicitly limited his survey to international adjudicative bodies that “bear a measure of commonality in that the provisional measures practice of each is linked—directly or indirectly—to that of the ICJ, which continues to function as a uniform point of reference (and occasional point of opposition) for the courts and tribunals considered” (p. 7). Is it not to be expected that courts and tribunals rooted in the traditions or culture of the same court are more likely to converge generally around that court's practice? Interestingly, the practice of these specific adjudicative bodies may also tend to converge because ICJ judges are known to serve with some regularity as arbitrators in investor-state dispute settlement (ISDS).Footnote ⁷ Similarly, it is common knowledge that several individuals have served not only as counsel in ICJ cases but also as arbitrators in ISDS, judges at ITLOS, or arbitrators in UNCLOS Annex VII Tribunals. In contrast, with some limited exceptions, it is relatively rare for the same individual to have served as counsel or judge in one or more of these bodies, as well as in regional or global human rights bodies.

Perhaps one of the motivations for excluding other bodies is simply the volume's length. Miles delves deeply and thoroughly into the work of the courts and tribunals he surveys. Yet the practice of other bodies, such as regional and global human rights bodies, could further strengthen the book's overarching thesis. Miles defends his exclusion of the European Court of Human Rights, the Inter-American Court of Human Rights, the African Court of Human and Peoples’ Rights, and the United Nations treaty bodies by positing that they “have developed a slightly different tradition of interim relief that has been the subject of extensive review elsewhere” (id.). First, much of the provisional measures practice of the adjudicative bodies surveyed has also been subject to review elsewhere,Footnote ⁸ although Miles thoughtfully expands upon and updates that review. Second, if the differences are “slight,” the practice of human rights bodies would only serve to reinforce Miles's argument.

Part III contains three chapters that contribute in meaningful ways to the utility of the book. It begins by considering distinct questions of substance and procedure, adding nuance to the “[]mostly[] … monolithic” depiction of provisional measures presented in Part II (p. 345). Specific situations where the principles of provisional measures are “bent or even broken” are highlighted (id.). For example, Miles discusses the unique way provisional measures function in cases involving human rights and humanitarian law and diplomatic protection, as well as cases in which the link between the provisional measures sought and the rights allegedly at risk of irreparable prejudice is attenuated or broken. Miles also devotes attention to interim relief in the context of the parallel seisin of the ICJ and the United Nations Security Council, and the use of provisional measures in cases involving parallel dispute settlement in either domestic or international bodies—the international equivalent of an anti-suit injunction. Given Miles's choice to highlight human rights and humanitarian law as specific areas where courts’ decision making in the provisional measures realm is somewhat distinct from other substantive areas, he might have considered whether these differences are also present in the work of the regional or global human rights bodies. Chapter 8 also helpfully considers provisional measures in the context of various procedures or phases in litigation, including advisory proceedings, non-appearing parties, interpretation proceedings, and ICSID annulment proceedings, in addition to modification or revocation of provisional measures.

Part III is also of particular use to practitioners before the international courts and tribunals surveyed because it contains a chapter explicitly devoted to the use of provisional measures in litigation strategy. Miles examines how an application for interim relief can be used for purposes beyond safeguarding rights pendente lite or preventing aggravation of a dispute. In so doing, he identifies and discusses costs and benefits to filing an application for interim relief. For example, litigants may wish to consider how such a request may help them to obtain information about future conduct of the proceedings and how it might influence the wider dispute, even when compliance by the other party is unexpected, and the extent to which the granting of interim relief is the underlying goal of the litigation. Miles then considers whether an application for provisional measures can constitute an abuse of process, and therefore, be deemed inadmissible. These questions are of obvious importance and utility to litigators advising their clients about the tactical value of filing a provisional measures request.

Miles concludes his book by summarizing his main findings and pointing out that although there exists no “uniform checklist” for ordering provisional measures in international law, there is an underlying logic to their commonality, albeit with room for “individual idiosyncrasy” (p. 475). In his view, a virtue of a common approach to interim measures is that it “increases the predictability of international judicial process and is acknowledged by prospective parties as being capable of producing a balanced outcome” (id.). Alternatively stated, perhaps a common “rule of procedural law” for international courts and tribunals enhances the acceptability of outcomes to those who utilize them.

Over time, the law and practice of provisional measures will continue to develop across substantive areas and in response to new and yet unimagined disputes. Miles's book provides a comprehensive and deep review of the existing law and practice of interim relief before the bodies surveyed, and is therefore, a must-read for those assessing the benefits and costs of an application for provisional measures or preparing a request for or response to a request for interim relief. The work also serves as an important resource for future theoretical and empirical work on procedural uniformity across international courts and tribunals, and hopefully, will spark further analysis on its possible implications for the legitimacy, effectiveness, and quality of international justice.