Mikhail Gorbachev and following the Chernobyl disaster of 1986 pursued this agenda. Gorbachev's policies of "glasnost" ("openness") and "perestroika" ("restructuring") and his reorientation of Soviet strategic aims contributed to the end of the Cold War. Under this program, the role of the Communist Party in governing the state was removed from the constitution, which inadvertently led to crisis-level political instability with a surge of regional nationalist and anti-communist activism culminating in the dissolution of the Soviet Union. Gorbachev later expressed regret for his failure to save the Soviet state, though he has insisted that his policies were not failures but rather were
Mikhail Gorbachev carried out only personnel shifts rather than structural change. Andropov encouraged Gorbachev to expand into policy areas other than agriculture, preparing him for future higher office. With Andropov's encouragement, Gorbachev sometimes chaired Politburo meetings. In April 1983, Gorbachev delivered the annual Lenin's birthday speech; this required him re-reading many of Lenin's later writings, in which the first Soviet leader had called for reform, and encouraged Gorbachev's own conviction that reform was needed. In May 1983, Gorbachev was sent to Canada, where he met Prime Minister Pierre Trudeau and spoke to the Canadian parliament. There, he met and befriended the Soviet