The Kennedy and Johnson administrations advocated a "flexible response" to containing communism, supporting a failed attempt by Cuban exiles to overthrow Fidel Castro, issuing a naval blockade with the threat of nuclear weapons during the Cuban Missile Crisis and deploying troops to prevent the spread of communism in South Vietnam, a decade-long struggle that caused domestic turmoil in the U.S. Containment also took place in more subtle ways. In the 1970s, President Nixon attempted to ease tensions with the Soviet Union. Nixon visited communist China and engaged in several diplomatic meetings with the Soviet leader. By the end of the decade, tensions once again escalated as the Soviet Union invaded Afghanistan. When President Reagan took office he denounced the Soviet Union as the "Evil Empire" and dramatically increased military budgets in an attempt to "win" the Cold War. Despite Reagan's contentious rhetoric, tensions between the two superpowers calmed in the late 1980s. Soviet leader adopted friendly relations with the west and instituted liberal domestic reforms through glasnost and perestroika. Reagan, Gorbachev, and British Prime Minister Margaret Thatcher met repeatedly to find common ground as the decade came to a close. In the end, the struggling Soviet economy led to the end of the Cold War. Weakened, the Soviets lost control of much of Eastern Europe by 1990. The fall of the Berlin Wall in November 1989 and the collapse of the Soviet Union in 1991 amounted to the end of the Cold War.
