This book assesses the changing international environment for humanitarian intervention to make two useful contributions. First, Wheeler uses case studies to underscore the evolving basis for intervention's legitimacy. India's invasion of East Pakistan in 1971, Vietnam's overthrow of Cambodia's Pol Pot regime in 1979, and Tanzania's use of force against Uganda in 1979 were all partially justified on humanitarian grounds but greeted by international skepticism. Only with the end of the Cold War and subsequent interventions in Iraq, Somalia, and Bosnia did a doctrine of U.N. Security Council-sanctioned intervention become legitimate. Second, the author credibly argues that governments do care about the legitimacy of their actions. Humanitarian intervention is not just a fig leaf for powerful states to cover their geopolitical pursuits but a result of shifting views within societies about acceptable behavior. And in response to skeptics who charge that intervention in the 1990s was still about power politics, Wheeler makes the case that humanitarian justifications -- even if inspired by cynical reasons -- can constrain subsequent government actions.