What impact will the Iraq war of 2003 have on international law governing the use of force and on the future of the United Nations Security Council? Some commentators have proclaimed that the military intervention led by the United States amounted to the “death” of the UN Charter and the end of “the grand attempt to subject the use of force to the rule of law.” The Security Council’s failure to reach agreement—in die face of French-U.S. antagonisms—spells the end, they argue, of an effective Council role in addressing major threats to peace and security. My own view is that it is premature to pronounce the “death” of the UN Charter or to give up on future prospects for Security Council agreement on the use of force. We are, nevertheless, at a difficult and precarious transitional moment in the international legal system governing the use of force, and the stark tensions reflected in the differences over Iraq are symptomatic of hard problems that may persist for the foreseeable future. Both the rules and the system need refining and reform. Success in doing so will require imagination and much greater willingness by policy makers to consider law’s potential role, not as a barrier to necessary action, but as a means to enhance global security in the face of emerging threats. In seeking such reform, it will be important to build upon the realism of the Charter’s founders, who combined rules governing the use of force with a clear commitment to credible enforcement action in response to threats to peace and security.