Under the Constitution, both the president and Congress have a role in foreign policy. Each has been given specific powers and has assumed additional authority either through precedent or by relying on other constitutional responsibilities. Since the Vietnam War, Congress has tried to exert more influence and control over foreign policy.
The president and foreign policy
The president negotiates treaties, appoints ambassadors to represent the United States overseas, and is commander in chief of the armed forces. Throughout U.S. history, presidents have used their power as head of the military to involve the nation in numerous conflicts abroad without a formal declaration of war by Congress, and they have found other ways to get around constitutionally imposed limitations on their ability to set the direction of American foreign policy.
Even though they are effective only during the term of the president who made them, executive agreements negotiated with another head of state do not require Senate approval. Presidents also have access to discretionary funds that can be (and have been) used to finance both military and diplomatic initiatives. Presidents routinely rely on special envoys, who do not require Senate confirmation, to carry out negotiations with other countries.
Congress and foreign policy
The constitutional function of Congress is essentially to act as a check on presidential power. Only Congress can declare war, and the Senate must approve all treaties and confirm the president's nominees for ambassadorial and cabinet positions. Congress has additional authority through its appropriation and oversight functions. As must all government programs, the operations of foreign policy must be funded. Congress can cut or increase foreign aid or the budget for a defense project. It can set restrictions on the length of time American troops are deployed during an international crisis by refusing to pay for them beyond a certain date. The Foreign Affairs and Intelligence Committees of both the House and the Senate have investigated the Iran-Contra affair as well as the operations of the Central Intelligence Agency (CIA).
Congress has used its power to make laws that specifically limit the freedom of action of the president in foreign policy. The Neutrality Acts (1935–1937) are an early example. The 1973 War Powers Act, which was a direct response to the Vietnam War, requires that Congress be consulted whenever the president is ready to commit American troops. It puts a 60-day limit on their deployment (with an additional month for withdrawal) without further congressional approval. Vetoed by President Nixon and generally opposed by his successors, the act's effectiveness has been questioned. Still, President George H. W. Bush sought the support of Congress before the Persian Gulf War, as did President Bill Clinton to send troops to Somalia and Bosnia. Congress also authorized the use of force in Iraq in the fall of 2002.
The mass media and foreign policy
The print and broadcast media play a role in setting the foreign-policy agenda for the country. Coverage of the Vietnam War is credited with bringing about the public-opinion shift in favor of withdrawal. Perhaps recalling Vietnam, the Defense Department severely restricted how the press could cover the Persian Gulf War. On the other hand, the images of starvation in Somalia and the graphic reports of "ethnic cleansing" during the civil war in Bosnia built support for American intervention in both of those countries.