The changing nature of war affects the law of armed conflict, at the same time as national security has now developed an internal as well as an external aspect. Traditional wars between nation states are no longer the rule. The nonstate actor as a threat has gained credence (popularly, terrorism and its claimed breeding ground in failed states), linked in practice to issues of intervention on the territory of states harboring such groups. In military circles, the idea of armed struggle between modern military forces and what were formerly called guerillas has now largely been replaced by the terminology of asymmetric warfare and the concept of intelligence and preventive action interchangeably within U.S. borders and overseas. And what are the nonmilitary issues overseas, given the accepted wisdom that problems in Iraq and Afghanistan are not accessible to purely military solutions? The genesis of this book lies in an examination of legitimacy, in the broadest sense, in terms of religion, ethics, and law in conjunction with events in Iraq, Afghanistan, and the so-called War on Terror. The concerns should not be understood in terms of winning or losing, but rather what they tell us about ourselves. We cast the net broadly in looking at the issues from differing domestic and foreign perspectives, because, unusually for the United States, foreign events seemingly have forced their way into our domestic lives. With the dual perspective cn mind, we initially focus on the domestic issues expressed in constitutional law terms, as well as support for U.S. foreign policy and public opinion, while subsequently addressing the international side from the armed conflict law and legal responsibility perspectives.