The return of the deferential Congress after September 11 was another chapter in the fluctuating balance of power in executive-legislative relations on foreign policy. The reason for this ebb and flow lies not in the Constitution but in politics. How aggressively Congress exercises its formal foreign policy powers turns foremost on whether the country sees itself as threatened or secure and to a lesser extent on how well the president handles foreign policy. Congress's action on the 2001 Use of Force Resolution, the 2002 Iraq Resolution, the U.S.A. Patriot Act, and other issues illustrates the nature of, and limits to, congressional deference.