From 2003 to 2006, followers of global politics were treated to an extraordinary spectacle: the head of an international organization defying its biggest financial backer and the world’s most powerful state—and emerging victorious from the confrontation. Formerly a fairly obscure international bureaucrat, Director General Mohammed El Baradei of the International Atomic Energy Agency (IAEA) defiantly resisted efforts by the George W. Bush administration to ostracize Saddam Hussein’s Iraq and the Iranian revolutionary government as nuclear troublemakers. Using his power to shape the public presentation of IAEA safeguards, however, El Baradei managed not only to hamper what he saw as a U.S. effort to build the case for a new war with Iran but also to win the Nobel Peace Prize for himself and his agency. U.S efforts to retaliate against him failed: he was elected to a third term in spite of U.S. attempts to unseat him that included eavesdropping on his conversations. Nor was the agency punished, as the United States joined other countries in boosting funds substantially for the Vienna-based organization.

For Robert Brown, El Baradei’s successful defiance points to a new phenomenon in international politics: the emergence of an international body with sufficient independent authority that it can force even its most powerful patron to bow to its will in some circumstances. In Nuclear Authority, Brown documents the evolution of the agency from a strictly controlled servant of its members with a limited mandate to a far more independent actor with a broad remit. He argues that existing political science theory does not account for this emergence: “Political scientists are therefore missing crucial aspects of the relationship between states and international organizations by characterizing their [international organizations’] power as subsequent effects of hegemony, joint decision making, collective expectations, social environments, legalization, or delegation” (p. 31). Instead, he argues for a “theory of international political authority” in which states seek the establishment of an independent authority, such as the IAEA, “when they find collective action impeded by policy uncertainty or conflicts of interest” (p. 3). However, such an organization’s authority or legitimacy within the international community is contingent upon its ability to navigate such obstacles by supplying what he describes as “policy impartiality” (technical expertise) and “behavioral impersonality” (universal and consistent application of international rules) within a policy domain.

Chronicling the history of the IAEA from its relatively humble beginning through its current incarnation, Brown contends that the agency’s political authority has grown as it has successfully met these tests. In each of the chapters, he also examines historic developments in five nuclear policy areas—nonproliferation, safety, security, peaceful uses, and disarmament—finding that the agency has evolved substantively in very different ways from what its founders foresaw. In particular, he notes how it is in the nonproliferation arena where the agency now has by far the greatest clout and to which it devotes the most resources, whereas early on, it was thought that serving as a supplier of nuclear technology and materials for peaceful uses would be where it would have the greatest role. He also seeks to demonstrate how alternative theories—from realist theories emphasizing U.S hegemony to social constructivist arguments for the importance of international norms—are unable to provide compelling explanations for these developments.

An historian, however, might be tempted to view the same information through a different lens. Brown emphasizes the slow accretion of the agency’s authority through repeated demonstrations of policy and technical expertise and diplomatic evenhandedness. However, it is in some ways the historic disjunctures that are most instructive.

To begin with, Brown’s model largely treats the demand for “policy impartiality” and “bureaucratic impersonality” as independent variables. But, in fact, a close reading of his well-researched history demonstrates otherwise. A key political decision often lies in whether or not to demand such goods from an international body—and these judgments largely fall to the key actors in the international system. As Brown’s history demonstrates, it was the Soviet and U.S dominance of the international system during the Cold War and their desire to maintain this bipolarity that laid the initial basis for the IAEA’s significant role in nonproliferation. Today’s IAEA safeguards system—legal and technical measures to prevent the diversion of nuclear material for use in nuclear weapons—stems in good measure from a series of political calls by key states in the 1960s to give the agency the lead role, most notably under the 1968 Nuclear Nonproliferation Treaty.

Such a decision was far from a preordained conclusion and was resisted by some in the U.S. Congress, for example, on the basis that the United States had carried out far more bilateral inspections by the time of the treaty’s negotiation than had the IAEA. But it was the need of the two superpowers to prevent the threat of new nuclear powers (most notably West Germany) from sparking a crisis between them that was key to striking a deal. And it was a period of relative harmony among the permanent members of the UN Security Council immediately after the end of the Cold War that was crucial to further strengthening the safeguards system.

By the same token, the IAEA clearly has technical expertise in areas such as nuclear safety and security, having published dozens of monographs and led hundreds of missions advising countries on how to improve practices in these areas. But some leading states, including the United States, believe that they have little to learn from the agency in this regard and contend that agency standards may be lower than their own. As a result, they see universal standards as a threat, not an advantage, and national regulators have largely untrammeled authority in these areas

At the same time, Brown’s invocation of “policy impartiality” and “bureaucratic impersonality” essentially seeks to treat the agency as a black box, capable of turning out consistent and reliable policy products no matter the inputs of internal political actors. Yet what emerges perhaps unintentionally from Brown’s tale is in some ways a more compelling story about the importance of individual directors in determining whether or not the agency has more or less political authority. The book shows how bold directors general like El Baradei and his pathbreaking predecessor Hans Blix were able to garner and implement new powers for the agency—and especially the Secretariat—in global nuclear policy.

Yet contrary to much of Brown’s underlying argument, he also demonstrates how the current director general, Yukiya Amano, has hewed a less independent line after being elected in a leadership contest with the support of leading powers, especially the United States. Despite an opening, the agency played only a marginal role in the response to the Fukushima accident and its aftermath, and Amano chose not to use the accident as an opportunity to push for new agency powers (as Blix had done with Chernobyl). Brown lauds Amano for explicitly supporting U.S. efforts to broaden the agency’s safeguards investigation in Iran concerning allegations that Tehran had carried out experiments on many of the steps that it would need to weaponize fissile material into a nuclear weapon, after ElBaradei had taken a more cautious and skeptical approach to the U.S. intelligence behind the allegations. Yet when the leading powers and Iran reached a nuclear deal last year (after the publication of the book under review), Amano was willing to quickly put aside his newfound powers and the weaponization investigation at their behest, offering a sharp contrast to Blix’s behavior vis–à-vis South Africa’s disarmament or El Baradei’s with Libya’s. Perhaps for the leading powers, the demand for bureaucratic impersonality at the IAEA has been superseded by the need for a bureaucratic personality at its helm who is more amenable to their interests.

Nonetheless, for those interested in nuclear matters or foreign policy, Nuclear Authority is a welcome addition to the limited and often out-of-date literature about this important international institution.