This massive tome seeks both to define the nature of security as it has changed in the post-Cold War period, and to outline the new regimes and institutions appropriate to it. "Cooperative security" is defined as a form of multilateralism that seeks to deal with new problems like ethnic conflict, state breakdown and proliferation. Several of the study's authors, including Defense Secretary William J. Perry, now work in the Clinton administration. Perry argues that forces should be sized for territorial defense alone; beyond that, there would be an international division of labor that would, in effect, sharply constrain the ability of the United States to intervene on its own. Whether this would be adequate to deal with powerful regional threats (like Iraq or Iran) in a timely manner is open to question. The book is animated by a clear preference for multilateralism over the unilateral use of American power. But while America cannot and should not seek to solve all international problems by itself, an important question remains whether a certain degree of unilateralism (a.k.a. "leadership") is not necessary to make the multilateral institutions work properly, as indicated by the floundering performance of the United Nations and NATO in Bosnia in recent months.