The world is going through another important transition. International institutions have unquestionably been weakened as the United States works to sort through complicated issues such as the Afghan and Iraq wars, the use of torture and secret detention, Guantanamo, climate change, and nuclear proliferation. In recent memory, top Bush Administration advisers have spoken and written about the powerlessness of international law and its irrelevance-or worse-for the United States. The worldwide public needs and deserves a more accurate account. In The Power and Purpose of International Law, Mary Ellen O'Connell provides such an account by explaining the purpose of international law and the powers of enforcement it has available to achieve its mission. International law supports order in the world and the attainment of humanity's fundamental goals of peace, prosperity, respect for human rights, and protection of the natural environment. The author argues that these goals can best be realized through international law, which uniquely has the capacity to bind even a superpower. It is also through international law that competing powers and divergent cultures can reach consensus. By exploring the roots of international law, and by looking at specific events in its history, this book demonstrates the why and the how of international law and its enforcement. It directly confronts the claim that international law is "powerless" and that working within the framework of international law is useless or counter-productive. As the world moves forward and reexamines international norms and institutions, it is crucial that both leaders and their citizens understand the true power and purpose of international law, and why humanity has persistently accepted it as true law.