<P> The Paris Peace Accords effectively removed the U.S. from the conflict in Vietnam . However, the agreement's provisions were routinely flouted by both the North Vietnamese and the South Vietnamese government, eliciting no response from the United States, and ultimately resulting in the communists enlarging the area under their control by the end of 1973 . North Vietnamese military forces gradually built up their military infrastructure in the areas they controlled and two years later were in a position to launch the successful offensive that ended South Vietnam's status as an independent country . Fighting begun almost immediately in its aftermath due to a series of mutual retaliations, and war had come again in March 1973 . </P> <P> Nixon had secretly promised Thiệu that he would use airpower to support the South Vietnamese government should it be necessary . During his confirmation hearings in June 1973, Secretary of Defense James Schlesinger was sharply criticized by some senators after he stated that he would recommend resumption of U.S. bombing in North Vietnam if North Vietnam launched a major offensive against South Vietnam, but by August 15, 1973, 95% of American troops and their allies had left Vietnam (both North and South) as well as Cambodia and Laos under the Case - Church Amendment . The amendment, which was approved by the U.S. Congress in June 1973, prohibited further U.S. military activity in Vietnam, Laos and Cambodia unless the president secured Congressional approval in advance . However, during this time, Nixon was being driven from office due to the Watergate scandal, which led to his resignation in 1974 . When the North Vietnamese began their final offensive early in 1975, U.S. Congress refused to appropriate additional military assistance for South Vietnam, citing strong opposition to the war by Americans and the loss of American equipment to the North by retreating Southern forces . Thiệu subsequently resigned, accusing the U.S. of betrayal in a TV and radio address: </P> <P> At the time of the peace agreement the United States agreed to replace equipment on a one - by - one basis . But the United States did not keep its word . Is an American's word reliable these days? The United States did not keep its promise to help us fight for freedom and it was in the same fight that the United States lost 50,000 of its young men . </P> <P> Saigon fell to the North Vietnamese army supported by Viet Cong units on April 30, 1975 . Schlesinger had announced early in the morning of April 29 the beginning of Operation Frequent Wind, which entailed the evacuation of the last U.S. diplomatic, military and civilian personnel from Saigon via helicopter, which was completed in the early morning hours of April 30 . Not only did North Vietnam conquer South Vietnam, but the communists were also victorious in Cambodia when the Khmer Rouge captured Phnom Penh on April 17, as were the Pathet Lao in Laos successful in capturing Vientiane on December 2 . Like Saigon, U.S. civilian and military personnel were evacuated from Phnom Penh, U.S. diplomatic presence in Vientiane was significantly downgraded, and the number of remaining U.S. personnel was severely reduced . </P>

List the provisions of the treaty of paris. which provision was the most important