communist soldiers infiltrated the south from 1961 to 1963. Kennedy's escalation, 1961–1963 In the 1960 U.S. presidential election, Senator John F. Kennedy defeated incumbent Vice President Richard M. Nixon. Although Eisenhower warned Kennedy about Laos and Vietnam, Europe and Latin America "loomed larger than Asia on his sights." In April 1961, Kennedy approved the Bay of Pigs Invasion, which ended in failure. In June 1961, he bitterly disagreed with Soviet premier Nikita Khrushchev when they met in Vienna to discuss key U.S.–Soviet issues. Only 16 months later, the Cuban Missile Crisis (16–28 October 1962) played out on television worldwide. It was the closest the Cold War came to escalating into a full-scale nuclear war, and the U.S. raised the readiness level of Strategic Air Command (SAC) forces to DEFCON 2. The Kennedy administration remained essentially committed to the Cold War foreign policy inherited from the Truman and Eisenhower administrations. In 1961, the U.S. had 50,000 troops based in South Korea, and Kennedy faced four crisis situations: the failure of the Bay of Pigs Invasion that he had approved on 4 April, settlement negotiations between the pro-Western government of Laos and the Pathet Lao communist movement in May ("Kennedy sidestepped Laos, whose rugged terrain was no battleground for American soldiers."), the construction of the Berlin Wall in August, and the Cuban Missile Crisis in October. Kennedy believed that yet another failure to gain control and stop communist expansion would irreparably damage U.S. credibility. He was determined to "draw a line in the sand" and prevent a communist victory in Vietnam. He told James Reston of The New York Times immediately after his Vienna summit meeting with Khrushchev, "Now we have a problem making our power credible and Vietnam looks like the place." Kennedy's policy toward South Vietnam assumed that Diệm and his forces had to ultimately defeat the guerrillas on their own. He was against the deployment of American combat troops and observed that "to introduce U.S. forces in large numbers there today, while it might have an initially favorable military impact, would almost certainly lead to adverse political and, in the long run, adverse military consequences." The quality of the South Vietnamese military, however, remained poor. Poor leadership, corruption, and political promotions all played a part in weakening the ARVN. The frequency of guerrilla attacks rose as the insurgency gathered steam. While Hanoi's support for the Viet Cong played a