air power to the conflict if any serious violations of the agreement took place. It was also assumed that U.S. financial and military aid would continue to be forthcoming at previous levels. On 1 July 1973, however, the U.S. Congress passed the Case–Church Amendment, legislation that all but prohibited any direct or indirect U.S. combat activities over or in Laos, Cambodia, and both Vietnams. On 7 November the legislative branch overrode Nixon's veto of the War Powers Act. During 1972–1973, South Vietnam had received $2.2 billion in U.S. assistance. In 1973–1974, that figure was slashed to $965 million, a more than 50 percent reduction. Nixon's growing political difficulties (especially the Watergate scandal) and the increasing antagonism between the legislative and executive branches over Vietnam policies, did little to dampen South Vietnamese expectations. Some among the Saigon leadership were more realistic in their appraisal. According to Republic of Vietnam Air Force (RVNAF) General Dong Van Khuyen: "Our leaders continued to believe in U.S. air intervention even after the U.S. Congress had expressly forbidden it ... They deluded themselves." The shock of reduced aid was compounded on 9 August, when Richard Nixon, the guarantor of South Vietnamese independence, was forced to resign from office. In October 1973, the Arab oil embargo began, and the resulting oil shock of 1973–74 caused a massive bout of inflation that largely destroyed the South Vietnamese economy with a spokesman for Thiệu admitting in a TV interview that the government was being "overwhelmed" by the inflation. One consequence of the inflation was the South Vietnamese government had increasing difficulty in paying its soldiers. Taking advantage of North Vietnam's period of recuperation in 1974, President Thiệu stretched his forces thin by launching offensives that retook most of the territory captured by PAVN forces during the land grab of 1973 and 15 percent of the total land area controlled by the PAVN at the time of the cease-fire. In April, Thiệu launched the Svay Rieng Campaign against PAVN strongholds in eastern Cambodia. This proved to be the last major offensive operation launched by the ARVN. While these operations succeeded, the cost in terms of manpower and resources was high. By the end of the year the military experienced shortages as a result of decreased American aid, while communist forces continued gaining strength. By the end of October the North Vietnamese Politburo decided on its strategy for 1975 and 1976.