Cold War (1985–1991) reduced some strategic arms unilaterally. Fundamental to the dissolution of the Soviet Union, the Gorbachev policy initiatives of Restructuring ("Perestroika") and Openness ("Glasnost") had ripple effects throughout the Soviet world, including eventually making it impossible to reassert central control over Warsaw Pact member states without resorting to military force. On June 12, 1987, Reagan challenged Gorbachev to go further with his reforms and democratization by tearing down the Berlin Wall. In a speech at the Brandenburg Gate next to the wall, Reagan stated: While the aging communist European leaders kept their states in the grip of "normalization", Gorbachev's reformist policies
Foreign relations of the Soviet Union power struggles and foreign intervention, requested the neighboring Soviet Union to send military aid. Soviet intervention was seen as a hostile invasion by the United States and its allies, who funded the counter-revolutionary Mujahadeen, and thus led to a return to hostilities which were greatly exacerbated in the following years. When Mikhail Gorbachev became the leader of the Soviet Union in 1985, he sought to restructure the Soviet Union to resemble the Scandinavian model of western social democracy and thus create a private sector economy. He removed Soviet troops from Afghanistan and began a hands-off approach in the USSR's relations