A singular development of the post Cold-War era is the use of military force to protect human beings. From Rwanda to Kosovo, Sierra Leone to East Timor, and more recently Libya to Côte d'Ivoire, soldiers have rescued some civilians in some of the world's most notorious war zones. Could more be saved? Drawing on over two decades of research, Thomas G. Weiss answers "yes" and provides a persuasive introduction to the theory and practice of humanitarian intervention in the modern world. He examines political, ethical, legal, strategic, economic, and operational dimensions and uses a wide range of cases to highlight key debates and controversies. The updated and expanded second edition of this succinct and highly accessible survey is neither celebratory nor complacent. The author locates the normative evolution of what is increasingly known as "the responsibility to protect" in the context of the global war on terror, UN debates, and such international actions as Libya. The result is an engaging exploration of the current dilemmas and future challenges for robust international humanitarian action in the twenty-first century.