Since 1999, the United Nations Intellectual History Project has produced over a dozen studies that trace the work and impact of the United Nations since its founding. In this impressive volume, the project's directors argue that there are really three United Nations: the formal arenas of interstate diplomacy, the UN staff and operations, and the closely associated nongovernmental organizations, experts, and consultants. It is out of a confluence of power politics, progressive activism, forum sponsorship, and commissioned scholarship that the UN has helped shape the global debate on peace, security, development, and human rights. Drawing on earlier studies, Jolly, Emmerij, and Weiss assess the body's contributions and failures, citing as a success the UN's promotion of development and human rights. The UN has pushed global thinking to embrace social and economic rights and protections for women and children and, beginning in the 1950s, helped build an international economic framework for national development and trade. Failures include its late response to the neoliberal ideas of the Washington consensus and its weak one to the special needs of the poorest countries. As the book makes clear, the UN is important as a site -- or as a sort of ecological environment -- for not just the exercise of power but also the exercise of imagination.