between the United States and North Vietnam in Paris. Negotiations stagnated for five months, until Johnson gave orders to halt the bombing of North Vietnam. At the same time, Hanoi realized it could not achieve a "total victory" and employed a strategy known as "talking while fighting, fighting while talking", in which military offensives would occur concurrently with negotiations. Johnson declined to run for re-election as his approval rating slumped from 48 to 36 percent. His escalation of the war in Vietnam divided Americans into warring camps, cost 30,000 American lives by that point and was regarded to have destroyed his presidency. Refusal to send more U.S. troops to Vietnam was also seen as Johnson's admission that the war was lost. As Secretary of Defense Robert McNamara noted, "the dangerous illusion of victory by the United States was therefore dead." Vietnam was a major political issue during the United States presidential election in 1968. The election was won by Republican party candidate Richard Nixon who claimed to have a secret plan to end the war. Vietnamization, 1969–1972 Nuclear threats and diplomacy U.S. president Richard Nixon began troop withdrawals in 1969. His plan to build up the ARVN so that it could take over the defense of South Vietnam became known as "Vietnamization". As the PAVN/VC recovered from their 1968 losses and generally avoided contact, Creighton Abrams conducted operations aimed at disrupting logistics, with better use of firepower and more cooperation with the ARVN. On 27 October 1969, Nixon had ordered a squadron of 18 B-52s loaded with nuclear weapons to race to the border of Soviet airspace to convince the Soviet Union, in accord with the madman theory, that he was capable of anything to end the Vietnam War. Nixon had also sought détente with the Soviet Union and rapprochement with China, which decreased global tensions and led to nuclear arms reduction by both superpowers; however, the Soviets continued to supply the North Vietnamese with aid. Hanoi's war strategy In September 1969, Ho Chi Minh died, aged seventy-nine. The failure of Tet in sparking a popular uprising caused a shift in Hanoi's war strategy, and the Giáp-Chinh "Northern-First" faction regained control over military affairs from the Lê Duẩn-Hoàng Văn Thái "Southern-First" faction. An unconventional victory was sidelined in favor of a strategy built on conventional victory through conquest. Large-scale offensives were rolled back in favour of small-unit and sapper attacks