Gabriella Blum's Islands of Agreement offers a pragmatic view of interstate relations and a refreshing perspective on conflict management. Arguing that some conflicts are not likely to be either prevented or resolved in the short-term, and that interstate relations are a continuum between peace and conflict, her primary focus is on areas (“islands”) of cooperation in the midst of enduring conflicts. These are wide-ranging, and include areas as diverse as environmental protection, participation in international institutions, and humanitarian assistance. Although Blum primarily draws upon three case studies—India and Pakistan, Greece and Turkey, and Israel and Lebanon—her theory has useful implications for other cases, including U.S.-Iranian relations in Iraq and Afghanistan, and international coordination to contain North Korea's nuclear program.

Blum highlights several characteristics of viable islands of agreement, many of which resemble features of other international institutions, which suggest broader applications beyond conflict management. These properties include divisibility from the primary issue of conflict, symmetrical costs and benefits, practicality, balanced clarity and ambiguity, and accountability mechanisms.

Blum's solid knowledge of her cases yields excellent comparative analysis to support her theory. I found interesting the many creative measures and mechanisms states design to regulate their relationships, ranging from simultaneous treaty signing to intricate notification procedures before weapons tests. Her work also highlights often-overlooked issues, suggesting that fruitful efforts for policymakers may lie in areas such as sports and humanitarian relief.

Islands of Agreement does suffer from a lack of theoretical clarity at some points. For instance, Blum explicitly focuses on islands as a middle stage of conflict management when prevention or resolution are not possible. However, this clarity is lost in the discussion and case analyses, where management is often conflated with at least nascent resolution. In addition, Blum distinguishes islands from traditional approaches to management by their ability to exist in the absence of a ceasefire; however, in all three cases, substantially diminished conflict seems a necessary even if not a sufficient condition for islands to emerge and be sustained.

Blum's work suggests several interesting fields for future inquiry. First, non-state actors are central players on the world scene. The significance of the project could be broadened by application to conflicts other than interstate wars. Since the cases examined involve both interstate and intrastate components, this task is already started. Second, the case studies suggest that public opinion and civil society can promote conflict management, and it would be interesting to explore further this nexus between domestic and international politics. Finally, there may be interesting variations in the extent or nature of islands based on the issue underlying the rivalry. For instance, territorial conflicts have unique properties; do they also have different scope or management possibilities?

Blum focuses on three cases and thus cannot necessarily generalize to other conflicts. However, she offers excellent analysis of these cases and a fresh perspective on an established area of inquiry. Since enduring rivalries comprise a significant proportion of conflicts today, her argument has important and thought-provoking implications for several disciplines dealing with conflict, including political science, public policy, economics, public health, psychology, sociology, and conflict resolution, and for professionals in NGOs and international organizations.