Reinventing Regional Security Institutions in Asia and Africa examines the causes of and processes within regional security institutions (RSIs). The study deploys process-tracing and historical institutionalism throughout, relying on a rich mix of primary and secondary sources collected through interviews, archival research, government reports, and thousands of documents obtained through fieldwork in Ethiopia, Indonesia, Nigeria, and Singapore. It is enriched by ambitious and robust fieldwork examinations spanning two continents (Asia and Africa) with two very different regional institutions in Africa (Economic Community of West African States [ECOWAS] and the Organization of African Unity [OAU]) and the Association of Southeast Asian Nations (ASEAN) in Asia.

The second chapter of the book outlines the theoretical framework adopted to analyze institutional change. To answer the research question of “why and how regional security institutions (RSIs) undertake change,” Kei Koga draws on agent-centered historical institutionalism in comparative politics, focusing on critical junctures, path dependence, and lock-in effects. The author identifies two processes for RSI institutional change: a macrolevel process triggered by external actors and microlevel change triggered by member states’ expectations and assessments of the RSI’s security utility (p. 26). Thus, the process of institutional change follows a two-step approach: (1) expected or actual changes in the regional distribution of power creates the conditions for an RSI’s institutional change, and (2) member states reassess their RSI’s security utility. In the face of actual or expected changes in the distribution of power, the outcome of the reassessment determines the type of institutional change: consolidation, displacement, or layering. RSI member countries interact with their regional institutions, making calculations about expected/actual change in the distribution of power and reacting according to their evaluations of their institutions. Member states will consolidate the current status if the evaluation is positive, will displace it if the outcome is negative, and will layer it if there is a high level of uncertainly among the members. This theoretical framework is then applied to three empirical cases.

Chapter 3 traces and explains two periods of institutional change within ASEAN: 1968–76 and 1988–97. The author finds that ASEAN endured many institutional changes and adaptations during the two time periods examined. Some of these changes took place because of external forces such as the United Kingdom’s dissolution of the Anglo-Malaysian Defense Agreement (AMDA), US-China rapprochement, and the United States’ Vietnamization policy.

Chapter 4 moves from Asia to West Africa with an examination of ECOWAS. The author considers two time periods here as well: 1976–81, marked by the creation of the Protocol of Mutual Assistance and Defense (PMAD), and 1989–99, marked by layering and consolidation (p. 118). Koga finds that institutional change in this case study came about through a combination of external triggers and member state expectations. The chapter makes two related arguments about institutional change within ECOWAS: “expected not actual change in the regional distribution of power triggered ECOWAS’s institutional change” and “ECOWAS member states’ divided expectations regarding the institution’s security did not prevent institutional change” (p. 120). Where there is a high level of uncertainly from member states, the author finds that layering occurs.

Chapter 5 considers the OAU by examining two periods of institutional change. The first one (1979–82) was marked by little security-related institutional change because of financial hardship (with the exception of a peacekeeping mission in Chad that the author argues was conducted to keep foreign powers out). The second period (1990–2002) was marked by institutional layering. The author argues that OAU’s institutional security preference (ISP) was founded on the non-interference principle. Koga argues that non-interference facilitated decolonization efforts, but hindered the objective of creating an African conflict-resolution mechanism (p. 163). Chapters 6 and 7 round out the analysis and summarize the book’s findings.

The in-depth analysis and rich empirical material used for the analysis make the book very interesting. The author takes issue with international relations theory (IRT) for several perceived limitations in the way it engages or studies institutions. The limitations of IRT, according to the author, are that it (1) treats all institutions monolithically, focusing primarily on their utility; (2) assumes that the functionality of international institutions is a given, instead of digging deeper into the processes of how norms come about; (3) fails to focus on RSIs created by non-great powers (i.e., IRT has a Western bias in its study of institutions); (4) fails to capture institutional change; and (5) fails to conduct comparative analyses across regions. Against this backdrop, the book certainly represents a welcome cross-fertilization between comparative politics and IRT. However, it does not successfully develop a clear and concise IRT theoretical framework that can be applied to other cases. Therefore, it might be read more as a work of comparative politics with a link to international relations.

Koga provides a much-needed contribution and a fresh empirical perspective by examining the RSIs of non-great powers. They are in stark contrast to, for instance, the United Nations, the European Union, and NATO, which are the most recurrent case studies in IR. The book also adds non-Western perspectives on the process and rationale behind institutional change, although it does not examine them, theoretically, far enough. The extensive fieldwork conducted by the author makes the empirical material very rich and positions this study as a unique perspective for conducting a cross-regional comparative analysis.

However, there are a few questions that need clarification and some choices that need further justification. First, including the OAU as a case study of an African RSI alongside ECOWAS is not justified. Why did the author not focus on other regional institutions in Africa, such as the East African Community or the South African Development Community, instead of focusing on the OAU? The dynamics, structures, and constraints of the OAU are vastly different from those of ECOWAS or other regional organizations. Second, by including institutions as different as ASEAN, OAU, and ECOWAS, the author falls into the problem of losing explanatory power because the overarching theoretical frameworks are too comprehensive. The richness of the scope of the analysis is thus at once a strength of this work and a weakness. It is a strength because not many studies (if any) have undertaken such a formidable task, and it is a weakness because the theoretical framework is made less rigorous by taking such a broad approach.

Lastly, the argument about member states’ calculations of actual/expected change and their decisions based on them to consolidate, displace, or layer is rather intuitive and self-evident. It does not present a provocative new perspective on how institutional change occurs. The book could have been stronger if it diverged from the literature typically used to analyze what the author describes as great-power institutions and developed a non-great-power framework for understanding institutional change from a non-Western perspective. In this respect, an interesting future project would be to deliver on the promise of expanding the literature on institutions beyond that exhibiting a Western bias by actually developing a novel theoretical framework that could then be applied to a particular set of non-Western empirical cases. With this being said, Reinventing Regional Security Institutions in Asia and Africa is a valuable contribution to IR scholars looking to branch out and learn more about institutional change.