The articles in this symposium issue of the Michigan Journal of International Law represent the product of a historic and path-breaking conference held at the University of Michigan Law School in February 2007. The two-day meeting brought together an extraordinary array of scholars and practitioners to examine closely the relevance of international law for the gathering of intelligence by states. Although this long-neglected topic has gained increased relevance since the use of more controversial intelligence-gathering methods by the United States as part of its “global war on terror,” many of the legal issues are as old as the craft of intelligence itself.