Nation building has been a prominent feature of U.S. foreign policy since the end of World War II, but in recent years it has become linked directly to national security. Building on recent important RAND studies on U.S. and UN efforts, this collection of essays by leading experts identifies the challenges involved and takes stock of the historical experience available to outsiders seeking to build nation-states. Fukuyama notes that the United States has been much more successful in assisting the reconstruction of war-torn or damaged societies -- such as in postwar Japan and Germany -- than in building states anew. A series of fascinating chapters recounts the postwar U.S. experience with promoting development and state creation, revealing its swings between optimism and failure. Later chapters look at the contemporary problems that have beset nation-building efforts in Afghanistan and Iraq. A theme that emerges is the striking absence of institutional memory and international capacity in these undertakings. Institutional lessons that were learned in Somalia, Haiti, and Bosnia were not effectively passed on to the Bush administration -- as has been painfully revealed by the ongoing U.S. occupation and reconstruction of Iraq.