A skillful explanation of the explosion of conflicts within the last 30 years arising from religious, cultural, linguistic, and territorial differences--and of the policies the US can pursue to defuse these tinderboxes. Callahan (State of the Union, 1997, etc.) gives comparatively cursory treatment to long-standing conflicts with steady but comparatively low casualty rates (e.g., northern Ulster), concentrating instead on those featuring a sudden paroxysm of destruction, including Biafra in 1968, Lebanon in the late 1970s, and Bosnia, Rwanda, and Chechnya in the 1990s. While acknowledging that America's handling of some ethnic conflicts has sometimes been adroit (e.g., Kosovo, the Baltic states), Callahan more often criticizes both Republican and Democratic administrations for mishandling crises. Sometimes mistakes arose from ideological blinders, as in the Nixon administration's unwillingness to recognize Bangladesh if it meant alienating Pakistan, a counterweight to what was seen as a more communist-leaning India. Other times the errors resulted from a preoccupation with other crises (e.g., when the Johnson administration, bedeviled by Vietnam, suddenly found itself facing the world's first TV images of mass famine from Biafra). Recognizing that a blanket policy on self-determination is self-defeating, Callahan offers useful guidelines that can be applied case by case. He warns bluntly that ``uncertainty and frustration are permanent features of post-cold war internationalism,'' and that Americans will have to accept that force will sometimes be misapplied, as in Somalia and Lebanon. Although Callahan dismisses the costs of intervention too quickly, he is more convincing in noting that many options short of overwhelming force exist to quell paroxysms of violence. Aside from intervention, he advocates larger American funding to further UN early conflict resolution and multinational peacekeeping, as well as improved State Department reporting on unrest within countries. An intelligent, sober, nonmoralistic argument for mediating ethnic strife before killing fields result.