The Eisenhower administration had opposed the peace settlement at Geneva in 1954, which divided Vietnam temporarily into two separate regroupment zones, specifically because the provision for future national elections opened up the possibility of placing the entire country under Communist rule. But President Eisenhower had been unwilling to introduce U.S. military forces to continue the conflict without the full support of the British and the French, who preferred to seek a negotiated settlement. In the end, Washington promised not to break the provisions of the agreement but refused to commit itself to the results. During the next several months, the United States began to provide aid to a new government in South Vietnam. Under the leadership of the anti-Communist politician Ngo Dinh Diem, the Saigon regime began to root out dissidents while refusing to hold the national elections called for by the Geneva Accords. It was widely anticipated, even in Washington, that the Communists would win such elections. In 1959, Ho Chi Minh, despairing of the peaceful unification of the country under Communist rule, returned to a policy of revolutionary war in the south. By 1963, South Vietnam was on the verge of collapse. Diem’s autocratic methods and inattention to severe economic inequality had alienated much of the population, and revolutionary forces, popularly known as the Viet Cong (Vietnamese Communists), expanded their influence throughout much of the country. In the fall of 1963, with the approval of the Kennedy administration, senior military officers overthrew the Diem regime. But factionalism kept the new military leadership from reinvigorating the struggle against the insurgent forces, and by early 1965, the Viet Cong, their ranks now swelled by military units infiltrating from North Vietnam, were on the verge of seizing control of the entire country. In desperation, President Lyndon Johnson (1908–1973) decided to send U.S. combat troops to South Vietnam to prevent a total defeat for the anti-Communist government in Saigon. Chinese leaders observed the gradual escalation of the conflict in South Vietnam with mixed feelings. They were undoubtedly pleased to have a firm Communist ally —and indeed one that had in so many ways followed the path of Mao Zedong—just beyond their southern frontier. Yet they could not relish the possibility that renewed bloodshed in South Vietnam might enmesh China in a new conflict with the United States. Nor could they have welcomed the specter of a powerful and ambitious united Vietnam that might wish to extend its influence throughout mainland Southeast Asia, which Beijing considered its own backyard. Chinese leaders therefore tiptoed delicately through the minefield of the Indochina conflict, seeking to maintain good relations with their ally in Hanoi while avoiding a confrontation with the United States. As the war escalated in 1964 and 1965, Beijing publicly announced that the Chinese people would give their full support to their fraternal comrades seeking national liberation in South Vietnam but privately assured Washington that China would not directly enter the conflict unless U.S. forces threatened its southern border. Beijing also refused to cooperate fully with Moscow in shipping Soviet goods to North Vietnam through Chinese territory. Despite its dismay at the lack of full support from China, the Communist government in North Vietnam responded to U.S. escalation by infiltrating more of its own regular force troops into the south, and by 1968, the war was a virtual stalemate. The Communists were not strong enough to overthrow the Saigon regime, whose weakness was shielded by the presence of half a million U.S. troops, but President Johnson was reluctant to engage in all-out war on North Vietnam for fear of provoking a global nuclear conflict. In the fall, after the Communist- led Tet offensive aroused heightened antiwar protests in the United States, peace negotiations began in Paris. Richard Nixon (1913–1994) came into the White House in 1969 on a pledge to bring an honorable end to the Vietnam War. With U.S. public opinion sharply divided on the issue, he began to withdraw U.S. troops while continuing to hold peace talks in Paris. But the centerpiece of his strategy was to improve relations with China and thus undercut Chinese support for the North Vietnamese war effort. During the 1960s, relations between Moscow and Beijing had reached a point of extreme tension, and thousands of troops were stationed on both sides of their long common frontier. To intimidate their Communist rivals, Soviet sources dropped the hint that they might decide to launch a preemptive strike to destroy Chinese nuclear facilities in Xinjiang. Sensing an opportunity to split the one-time allies, Nixon sent his emissary Henry Kissinger on a secret trip to China. Responding to the latter’s assurances that the United States was determined to withdraw from Indochina and hoped to improve relations with the mainland regime, Chinese leaders invited President Nixon to visit China in early 1972. Incensed at the apparent betrayal by their close allies, in January 1973 North Vietnamese leaders signed a peace treaty in Paris calling for the removal of all U.S. forces from South Vietnam. In return, the Communists agreed to seek a political settlement of their differences with the Saigon regime. But negotiations between north and south over the political settlement soon broke down, and in early 1975, convinced that Washington would not intervene, the Communists resumed the offensive. At the end of April, under a massive assault by North Vietnamese military forces, the South Vietnamese government surrendered. A year later, the country was unified under Communist rule. The Communist victory in Vietnam was a humiliation for the United States, but its strategic impact was limited because of the new relationship with China. During the next decade, Sino-American relations continued to improve. In 1979, diplomatic ties were established between the two countries under an arrangement whereby the United States renounced its mutual security treaty with the Republic of China in return for a pledge from China to seek reunification with Taiwan by peaceful means. By the end of the 1970s, China and the United States had forged a “strategic relationship” in which each would cooperate with the other against the common threat of Soviet “hegemonism” (as China described Soviet policy) in Asia.