These essays illuminate the ethical, legal, and political conditions under which humanitarian intervention can be justified, while revealing the dangers and complexities of such force. Several essays center on the legal debate that seeks to identify principles and precedents for new doctrines of humanitarian intervention. But a few authors also argue that such doctrines can be abused by powerful states -- indeed, principles of sovereignty provide a necessary bulwark for the weak against such abuse. Other essays focus on ethical questions and offer more basic challenges to constraints on the use of force inherent in prevailing international law or the un charter. The Kosovo intervention appears repeatedly as emblematic of the thorny tradeoffs between the protections of sovereignty and the necessity of humanitarian action. In a final set of essays focusing on political issues, Keohane argues that sovereignty in troubled societies must be "unbundled" to allow the reinforcement of domestic sovereignty, which strengthens the institutions of self-governance, and the abandonment of external sovereignty in favor of sustained international involvement. No other volume on humanitarian intervention better showcases the diverse intellectual terms or political stakes currently in play.