making decisions without discussing or confirming them with the Politburo. Leonid Brezhnev, a close companion of Khrushchev, was elected the first secretary the same day of Khrushchev's removal from power. Alexei Kosygin became the new premier and Anastas Mikoyan kept his office as chairman of the Presidium of the Supreme Soviet. On the orders of the Politburo, Mikoyan was forced to retire in 1965, and Nikolai Podgorny took over the office of chairman of the Presidium. The Soviet Union in the post-Khrushchev 1960s was governed by a collective leadership. Henry A. Kissinger, the American National Security Advisor, mistakenly believed that Kosygin was the leader of the Soviet Union and that he was at the helm of Soviet foreign policy because he represented the Soviet Union at the 1967 Glassboro Summit Conference. The "Era of Stagnation", a derogatory term coined by Mikhail Gorbachev, was a period marked by low socio-economic efficiency in the country and a gerontocracy ruling the country. Yuri Andropov (aged 68 at the time) succeeded Brezhnev in his post as general secretary in 1982. In 1983, Andropov was hospitalized and rarely met up at work to chair the politburo meetings due to his declining health. Nikolai Tikhonov usually chaired the meetings in his place. Following Andropov's death fifteen months after his appointment, an even older leader, 72-year-old Konstantin Chernenko, was elected to the general secretariat. His rule lasted for little more than a year until his death thirteen months later on 10 March 1985. At the age of 54, Mikhail Gorbachev was elected to the general secretariat by Politburo on 11 March 1985. In May 1985, Gorbachev publicly admitted the slowing down of the economic development and inadequate living standards, being the first Soviet leader to do so while also beginning a series of fundamental reforms. From 1986 to around 1988, he dismantled central planning, allowed state enterprises to set their own outputs, enabled private investment in businesses not previously permitted to be privately owned, and allowed foreign investment, among other measures. He also opened up the management of and decision-making within the Soviet Union and allowed greater public discussion and criticism, along with the warming of relationships with the West. These twin policies were known as perestroika (literally meaning "reconstruction", though it varies) and glasnost ("openness" and "transparency"), respectively. The dismantling of the principal defining features of Soviet communism in 1988 and 1989 in the Soviet Union