Jessica Howley has produced a significant intervention in the debates concerning claims in international law, specifically, those of states, on the one hand, and those of individuals, on the other. As the title suggests, these “overlapping” claims often intersect with, inter alia, diplomatic protection, counter-measures, and state responsibility. Howley clearly felt that the International Law Commission’s Articles on State Responsibility (ARSIWA) has left a visible gap in how claims can be brought before international tribunals since it excludes how individuals can invoke responsibility. Hence, in six carefully argued chapters, she is not only defensive but also adamant that the public–private gap in the international legal process, as it were, requires in-built mechanisms during treaty negotiations in order to provide legal certainty. Specifically, by placing limitations in advance, individuals can be made aware of future restraints.

Howley draws on two treaty-based mechanisms to show how diplomatic protection and certain “mixed” interstate claims differ under the local remedies rules. The two treaties in question are the ICSID ConventionFootnote ¹ and the CARICOM Treaty.Footnote ² The invocation of the CARICOM Treaty makes for an interesting read since it is often not given its due in international legal process, but here, Howley elevates the CARICOM Treaty, despite being a regional treaty for Caribbean states, to the centre of international diplomatic protection. The implication, therefore, is that similar regional treaties, such as ASEAN or others in Asia with dispute settlement mechanisms, fall within the rubric of overlapping claims vis-à-vis those of the state and individuals. Howley, pointing to the relevant provision under the CARICOM Treaty (Article 222(c)), notes how individuals may bring claims before the regional court and the Caribbean Court of Justice (CCJ), while, at the same time, the ICSID Convention under Article 27 allows for an individual’s consent to arbitration of claims “to prevent their national State from bringing a claim” (at 59). Hence, the ICSID Convention and the CARICOM Treaty “allow for an individual or State conduct to preclude an overlapping claim from being brought by the other” (at 59). While Howley explores other arguments and the role of other treaties throughout the book, it is evident that the discussions of the ICSID Convention and the CARICOM Treaty helped to answer questions relating to the role of public international law in overlapping claims (at 7).

Howley’s views are certainly welcome, and they are likely to catch the attention of international tribunals and the evolving scholarship in the field. For one, it has brought back to life the classical field of diplomatic protection, albeit not in the form of a dedicated monograph. In addition, the treatment of regional treaties, such as the CARICOM Treaty, suggests that other tribunals will follow the cases emanating from the dispute settlement system (the CCJ) more intently.

At the same time, state interests are still fundamental to how international tribunals and international law by and large interpret historical, present, and evolving rules. This then begs the question of whether the local remedies rules, by way of example (and as discussed in Howley’s work) are sufficient to apply the terms of the ICSID Convention and the CARICOM Treaty vis-à-vis individual claims, to deny a State claim. Nevertheless, Howley has done an exemplary job in this book and it is to be welcomed as part of the debate on international litigation and the underlying rules governing claims in international law.