Chapter 1 introduces the figure of the foreign fighter in the interwar period by focusing on the Spanish Civil War. It shows how the image of the nineteenth-century adventurer haunts the imaginary of the actors preoccupied with finding a legal status for the volunteers in Spain. This image is nonetheless constantly split in two: idealists and freebooters; heroes and opportunists; barbaric troops and brave highlanders. The chapter moves from the League to the Anglo-American doctrine, to domestic discussions and ends at The Hague in 1907. It is there that rules on foreign volunteers are codified in an international convention for the first time. The chapter further links the Brussels Conference of 1874 to those of Geneva in 1949 and offers a lens through which to understand how the shifting image of the adventurer reaches the decolonization period.

The conclusion of the book draws together the findings from the statistical analysis and the case studies, suggesting possible nuances and extensions to the theoretical framework. It further explores the financial statecraft of borrowers through short accounts of external finance and aid negotiations in Uganda, Senegal, and Laos. The chapter spells out policy implications of the argument, suggesting steps that policymakers in developing countries can take to derive the greatest benefit from their portfolio of external finance, as well as ways that traditional donor agencies can maintain and enhance their relevance. It concludes with reflections on the pertinence of the book's findings for developing countries in debt crisis, including those negotiating debt relief with diverse creditors.

Chapter 2 explains how belligerent reprisals have come to be interpreted as tools to induce compliance with the laws of armed conflict. It does so by highlighting three cumulative processes. First, it looks at the role that post–World War II tribunals, the ICTY and the ICRC have played in stressing the procedural elements of belligerent reprisals, emphasizing the highly formalized set of steps to be taken before the adoption of the measure while downplaying the retaliatory act itself. Then, it claims that the main thrust of this proceduralization lies in the creation of a regulatory framework that attributes a specific legal meaning to the retaliatory conduct and, by so doing, allows for an assimilation of belligerent reprisals with the notion of countermeasures. In turn, this analogy leads to the attribution to belligerent reprisals of a sanctioning character that protects the primary norm from the risk of persistent non-compliance. The outcome of these three processes is the attribution to belligerent reprisals of a chiefly coercive purpose, interested in inducing compliance with the laws of armed conflict and markedly influenced by the enforcement paradigm.

Chapter 3 examines mythical, historical, and scientific facts. It offers a brief history of East Asian international relations, paying particular attention to the Chinese World Order, the Khmer Empire, and post-colonial Filipino historiography as samples for how to theorize histories from an IR perspective. The chapter discusses war and peace as well as political economy, the subject matters important for East Asian history and IR theory. It also offers a section on impacts and lessons of history, illustrating how history contributes to background knowledge, historiography and belief systems, foreign policy analysis, and IR theory. A better understanding of East Asian history allows us to contextualize contemporary issues without which we may not be able to put together a puzzle. Historical experiences inform our belief system, into which people typically fit new events or factors as explanation. History is evolutionary by nature, whether we frame it that way explicitly or not.

Chapter 6 inquires into the legality and purposes of belligerent reprisals in non-international armed conflict. At the outset, it delves into the travaux préparatoires of Additional Protocol II to the 1949 Geneva Conventions to overcome the paucity of black-letter provisions on belligerent reprisals in this type of conflicts and identify relevant practice indicating which reprisals are prohibited (and which are permissible). Then, it looks into the work of several fact-finding commissions, mandated investigations and expert bodies addressing situations of non-international armed conflict (including those in Myanmar, South Sudan, Yemen and Syria) to gauge their formalization of the mechanism. The re-instatement of reciprocity in the functioning of belligerent reprisals emerges clearly from the purpose of evening out the legal and substantive imbalance brought about by enemy breaches. This analysis results in a novel understanding of belligerent reprisals as a tool concerned with the overall equilibrium in the legal relationship between parties to the conflict and aimed at remedying their inequality of status.

The Introduction explains the relevance of a theoretical inquiry into the purpose and function of belligerent reprisals. It highlights several examples in recent practice where the vocabulary of belligerent reprisals has been harnessed by parties to an armed conflict, pointing to the continued relevance of the institution in contemporary warfare. At the same time, it outlines persisting difficulties in the terminology, regulation and governance of reprisals, and shows that they all derive from the failure by international legal theory to give a proper legal vest to the purpose and function of the mechanism. It points to fundamental fallacies both in how the question has been approached, and in how it has been answered. It proposes an alternative to existing accounts and outlines how it will be investigated in the book.

Chapter 5 analyzes the evolving security structures in East Asia since the end of World War II. What counts as security for the countries in the region and beyond, and the policy choices made accordingly, have made East Asian security the way it is today. Evolution shapes every component of international security, specifically the nation, the nature of politics, and epistemology. Conventional security theories such as the security dilemma and alliance apply to East Asia partly because Western practice and theory have become parts of East Asian practice and theoretical thinking. At the same time, East Asia had a much longer history, and was not a blank canvas for outside influence. The mixture of the old and new explains why East Asian security concepts and practices seem partly familiar and partly strange, which is characteristic of East Asian international relations.

The Conclusion draws on the findings of the book to analyse the main implications of a reciprocity-based understanding of belligerent reprisals. First, it distinguishes this formalization of belligerent reprisals from earlier theories stressing the law-making function of the measure. Then, it accounts for the continued relevance of belligerent reprisals even at a time when mechanisms monitoring and enforcing compliance with the laws of armed conflict gain momentum. Finally, it explains how a reciprocity-based interpretation of belligerent reprisals would affect follow-up reform of the mechanism – be it in the sense of fine-tuning its regulation, or in the sense of disposing of it altogether.