Cooper–Church Amendment

The Cooper–Church Amendment was introduced in the United States Senate during the Vietnam War. The proposal of the amendment was the first time that Congress had restricted the deployment of troops during a war against the wishes of the president.

The amendment sought to:
 * 1) End funding to retain U.S. ground troops and military advisors in Cambodia and Laos after 30 June 1970
 * 2) Bar air operations in Cambodian airspace in direct support of Cambodian forces without congressional approval
 * 3) End American support for Republic of Vietnam forces outside territorial South Vietnam.

The amendment was presented by Senators John Sherman Cooper and Frank Church and attached to a major bill, the Foreign Military Sales Act (HR 15628). After a seven week filibuster and six months of debate, the amendment was approved by the Senate by a vote of 58 to 37 on 30 June 1970. The bill failed in the House of Representatives, which opposed inclusion of the amendment by a vote of 237 to 153. President Richard M. Nixon threatened to veto the bill if it contained the Cooper–Church provisions, and the foreign assistance bill was subsequently passed without it.

A revised Cooper–Church amendment, Public Law 91-652, passed both houses of Congress on 22 December 1970, and was enacted on 5 January 1971, although this version had limited restrictions on air operations and was attached to the Supplementary Foreign Assistance Act of 1970. By that time, U.S. ground forces had already officially withdrawn from Cambodia, while U.S. bombing missions in Cambodia (Operation Freedom Deal) continued until 1973. The Nixon administration denounced all versions of the amendment, claiming that they harmed the military effort and weakened the American bargaining position at the Paris peace talks.

Author David F. Schmitz stated that the amendment was a landmark in the history of opposition to the war, congressional initiatives to bring the fighting to an end, and efforts to control executive power in foreign policy.