Presidency of Ronald Reagan to forestall the possibility of an agreement between the United States and the Soviet Union. Nonetheless, both Gorbachev and Reagan agreed to continue arms control negotiations at the October 1986 Reykjavík Summit. At the summit, Gorbachev and Reagan closed in on an agreement to greatly reduce or eliminate the nuclear stockpiles of both the U.S. and the Soviet Union over a ten-year period, but the deal collapsed due to disagreements regarding SDI development. Reagan attacked Gorbachev in a 1987 speech delivered in West Berlin, but negotiations continued. Gorbachev and Reagan broke the impasse by agreeing to negotiate separate treaties on
Jack F. Matlock Jr. Reagan rejected the proposals. Gorbachev began a period of internal economic restructuring, known as perestroika, and agreed to a series of summits with the American president. Matlock was instrumental in preparing Reagan for his first summit with Gorbachev, arranging for specialists within the government to write a "Soviet Union 101" course of 21 papers on Russia for Reagan to study. Matlock also participated in a mock summit, playing the role of Gorbachev, allowing Reagan to practice the encounter in advance. Speaking at a Chautauqua conference in Jūrmala, Latvia in June 1986, Matlock told the crowd that the United States did