These works join an abundance of recent scholarship on the United Nations Security Council, an institution that has been unleashed since the end of the Cold War to serve not only its intended purpose, as envisioned in the UN Charter, but also a variety of new functions in international security and law. The books complement each other well. They cover much of the same empirical territory, and both adopt a social constructivist perspective to shed light on the evolution of Council activities.

Building especially on the work of Nicholas Onuf, Brian Frederking adopts the lens of “rule-oriented constructivism,” which sees global politics as governed by a set of social rules that both constitute reality—defining actors, their situations, and their choices—and regulate behavior by telling actors the actions that are permissible. By adopting a social rather than material ontology, he assumes that material structures, such as the distribution of military capabilities, have meaning “only within the context of social rules” (p. 7). States are nevertheless strategic. They are “communicatively rational” and use arguments and language to make claims, which are then evaluated by others and either accepted or rejected—a process that, in turn, reconstructs social rules over time.

Frederking uses this foundation to create a typology of “global security arrangements”; the four ideal-types are war, rivalry, collective security, and security communities—based on various configurations of security rules that govern the international system. He then uses this framework to make both positive and normative points. The positive argument is that many of today's conflicts over security issues boil down to a tension between the United States—which often prefers a hierarchical approach associated with hegemony, preventive war, and empire—and other states—which prefer less hierarchy and more multilateralism. The normative argument is that in today's world of transnational issues and security interdependence, the most appropriate system is one of collective security. American power alone cannot provide global security. An important upshot of this discussion is the existence of what Frederking terms the “security-hierarchy paradox”: Some leadership is necessary on the part of the United States to promote and enforce rules that address today's security threats, but too much of this hierarchy is counterproductive as it lacks legitimacy and undermines international institutions.

The empirical portion of The United States and the Security Council consists of chapters on peacekeeping, economic sanctions, the use of force, international tribunals, weapons proliferation, human rights, and terrorism, with a focus on conflicts and debates among the five permanent members of the Security Council. These case studies are engaging and cover many important post–Cold War issues in a clear and updated way. They focus on describing the evolution of international practice in these areas and on demonstrating a tension between U.S. interests and those of its major-power counterparts in terms of both substance and approach.

The main weakness of the book is that the empirics are uneven in the extent to which they speak to the theoretical arguments presented in the early chapters. Frederking sets a high empirical bar for his version of constructivism. He notes that “[t]o understand an act, one must know an agent's contextual understanding of the situation. One must know the reason for the action” (p. 9). To apply his theory, one must know both the intentions of the actor and how others interpret the relevant behavior (p. 15). And yet the type of evidence offered is quite general—mostly based on press accounts, UN reports, and secondary academic literature—and not especially well suited to the research task. Moreover, most chapters confine theoretical discussion to a brief concluding section, and the book's concluding chapter is too short—only two pages—to synthesize the evidence and systematically outline theoretical implications. Nevertheless, Frederking's framework offers a useful lens for understanding today's clashes over important policy issues and makes the compelling suggestion that they arise from deeper differences over global security norms.

Bruce Cronin and Ian Hurd are interested in explaining the authority of the Security Council, both its origins and effects, and they devote the first two chapters of their edited volume to theory and method. The introductory chapter, coauthored by the editors, defines the key theoretical constructs of power, authority, and legitimacy and their relationship to one another—a contribution to the literature that is valuable in its own right. Authority is a hierarchical relationship in which one actor or institution is viewed as having the right to make decisions on behalf of the entire community. In other words, for Cronin and Hurd, authority is legitimized power. Organizations gain legitimacy—and thus wield authoritative power—when their goals are consistent with the broader norms and values of society (purposive legitimacy), when decisions are based on open deliberation and consistent procedure (deliberation legitimacy and procedural legitimacy), and when they are effective (performance legitimacy). Thus, like Frederking, they view the Council's influence as a function of social as well as material factors.

The UN Security Council and the Politics of Interntional Authority is centered on various questions raised by Cronin and Hurd, and on one overarching hypothesis: “The scope and depth of the Security Council's authority expands and contracts proportionately with the degree of legitimacy that the membership grants it” (p. 18). Of course, these are slippery concepts, and thus Chapter 2 is an attempt by Hurd to outline how one might observe and test for the authority and legitimacy of the Council and other institutions. He settles on two empirical strategies. First, we should see that states feel the need to justify their behavior to the institution (which, he argues, is more informative than merely looking at compliance behavior). Second, we should see that states have internalized the institution's legitimacy such that it enters into their decision making automatically. There are limits to these measures, to be sure, but the exercise is useful and advances a literature that has not stressed research design issues.

The empirical portion of the book contains seven chapters by an eclectic group of scholars. These contributions vary in the extent to which they speak to the main questions raised by the editors. Wayne Sandholtz, Ian Johnstone, and Cronin offer the most systematic assessments of different aspects of Council authority in the context of criminal tribunals, terrorism resolutions, and the implementation of international law, respectively. Others depart substantially from the editors' framework. For example, Erik Voeten offers a rationalist alternative explanation for the Council's influence; Jonathan Graubart focuses mostly on the authority of nongovernmental organizations, not the Council; and Jean Krasno and Mitushi Das explore General Assembly legitimacy as an alternative to the Council when there are threats to peace and security. In the end, these departures do not detract from the volume since the individual chapters are make rich contributions on their own.

The empirical chapters offer striking examples of an organization that has dramatically expanded the scope of its activities. However, on the central theoretical questions of legitimacy and authority, the overall picture is a bit murky. First, multiple authors looking at the same institution—and even the same issue—seem to disagree in their assessments of legitimacy. Thus, Johnstone looks at the Council's resolutions on terrorism and finds substantial legitimacy, based in deliberation and procedure, whereas George Andreopoulos looks at the same matter and finds an organization devoid of transparency and accountability and thus utterly lacking in legitimacy. The presence of purposive legitimacy, in particular, seems to be in the eye of the beholder. While Cronin and Sandholtz find that the Council pursues goals consistent with international community norms, Voeten, Graubart, and Andreopoulus see decisions that reflect the interests of a more narrow set of (largely powerful) states. Second, the questions of how much and which forms of legitimacy are required for authority to take hold are not answered. Is one of the four pillars of legitimacy sufficient to lend authority to an institution, or are more required? The authors offer different, often only implicit, answers.

Anyone interested in the Security Council or international organizations more generally will find these books stimulating. In offering novel theoretical takes on the Council's evolution since the end of the Cold War, they join a number of recent volumes that improve our understanding of the Council and its relationship to the United States (e.g., Hurd, After Anarchy: Legitimacy and Power in the UN Security Council, 2007; David M. Malone, ed., The UN Security Council: From the Cold War to the 21^st Century, 2004; and Alexander Thompson, Channels of Power: The UN Security Council and U.S. Statecraft in Iraq, 2009). These books also illustrate the difficulty that international relations scholars have in studying international organizations as social scientists. Our theoretical advances tend to outstrip our ability to draw firm empirical conclusions about the fascinating and important—but terribly complicated—world we study.