Since the Vietnam War, Congress has played a more active and public role in the foreign policy process. The ability of Congress to make foreign policy, however, is constrained by many institutional factors. In addition, the relationship between Congress and the president is often filled with conflict, leading to gridlock and chaotic policy making on a variety of international issues, from military intervention to foreign aid. As this chapter highlights, Congress has the ability to influence procedural aspects of foreign policy, such as which actors are involved and how they participate, as well as a number of other tools at its disposal to influence the foreign policy agenda.

Consensus between the president and Congress on foreign policy issues has ebbed and flowed. Congressional committees and representatives have become increasingly involved in foreign policymaking. The situational context of Congress in terms of its relationship with the White House ranges from compliance to independence. This context of the relationship depends largely on the particular foreign policy issue. Yet, as this chapter reviews, the terrorist attacks of September 11 led to bipartisan deference to the president on foreign policy. Congress continues playing an oversight role in the foreign policy process by passing legislation that determines how the president and bureaucracy conduct foreign affairs. Despite these limitations Congress has been successful in foreign policymaking by influencing government procedure. However, not all procedural reforms are not always successful. Congress also manages and approves the budgetary aspects of foreign affairs; the power of the purse is the most important way in which legislators influence foreign policy.