On March 11, 1985, Mikhail Gorbachev became General Secretary of the Communist Party of the Soviet Union. His push for reform at home and a less confrontational approach abroad created new openings for U.S.-Soviet diplomacy. This leadership change helps mark the start of the 1985–1991 phase of end-of-Cold-War relations.
From November 19 to 21, 1985, President Ronald Reagan and General Secretary Gorbachev held their first summit in Geneva. While no major treaty was signed, the meeting restarted top-level dialogue after years of tension and helped set a more practical tone for arms control talks. It also established a working relationship that carried into later negotiations.
On April 26, 1986, Reactor 4 at the Chernobyl nuclear power plant exploded and burned, releasing large amounts of radiation. The scale of the disaster and the Soviet government’s early secrecy increased pressure for greater openness (often linked to glasnost, or public transparency). It also worsened the Soviet Union’s economic and political strain during a period when Moscow was seeking arms control and calmer relations with the West.
On October 11–12, 1986, Reagan and Gorbachev met in Reykjavík, Iceland, to explore deep reductions in nuclear weapons. Talks collapsed mainly over disagreements about U.S. missile defense research (the Strategic Defense Initiative, or SDI). Even so, the summit clarified what each side could accept and helped pave the way for a more focused treaty on intermediate-range missiles.
On June 12, 1987, Reagan spoke near the Brandenburg Gate in West Berlin and publicly challenged Gorbachev to open the Berlin Wall. The speech reflected how diplomacy and symbolism were being used together: negotiations continued, but public messages about freedom and political change also mattered. It became one of the most remembered U.S. statements of the late Cold War era.
On December 8, 1987, Reagan and Gorbachev signed the Intermediate-Range Nuclear Forces (INF) Treaty in Washington, D.C. The agreement required both sides to eliminate an entire class of ground-launched missiles with ranges of 500–5,500 km, with intrusive verification measures. It was a major turning point because it reduced weapons rather than just limiting future growth.
From May 29 to June 2, 1988, Reagan traveled to Moscow for a summit with Gorbachev. Coming after U.S. Senate approval, the leaders advanced steps needed to put the INF Treaty into effect and broadened talks to other regional conflicts and human rights issues. The visit signaled that sustained, structured negotiations had replaced earlier cycles of crisis and suspicion.
On February 15, 1989, the Soviet Union withdrew its last troops from Afghanistan, ending a long and costly intervention. The war had badly damaged East-West relations and drained Soviet resources. Leaving Afghanistan supported Gorbachev’s broader effort to reduce foreign commitments while seeking more stable ties with the United States.
On November 9, 1989, East German authorities opened border crossings, and crowds began moving freely between East and West Berlin. The event symbolized the rapid weakening of Soviet-backed communist governments in Eastern Europe and made German reunification a realistic near-term issue. For U.S.-Soviet relations, it tested whether Moscow would use force—or accept change through political negotiation.
On December 2–3, 1989, President George H. W. Bush and Gorbachev met at the Malta Summit. The meeting is widely seen as a key marker of the Cold War’s end, as both leaders emphasized cooperation while Europe’s political map was changing quickly. It also began the Bush administration’s main phase of managing the transition from rivalry to negotiated security changes.
On September 12, 1990, the Treaty on the Final Settlement with Respect to Germany (the “Two Plus Four” Treaty) was signed by East and West Germany and the four World War II occupying powers: the United States, the Soviet Union, the United Kingdom, and France. It cleared the way for German reunification and defined limits and conditions for Germany’s sovereignty and security. The agreement showed U.S.-Soviet cooperation extending beyond arms control to reshaping Europe’s postwar order.
On July 31, 1991, Bush and Gorbachev signed the Strategic Arms Reduction Treaty (START I) in Moscow. The treaty set major limits on intercontinental missiles and nuclear warheads, paired with verification rules to track compliance. It capped the end-of-Cold-War arms control process with the largest negotiated reductions in the superpowers’ strategic nuclear forces up to that point.
On December 25, 1991, Gorbachev resigned as president of the Soviet Union, transferring key powers— including control of nuclear forces—to Russia’s president, Boris Yeltsin. The resignation came at the end of a year of political breakup across the Soviet republics and signaled that the USSR’s role as a superpower rival was finished. This moment provides a clear closing outcome for 1985–1991 U.S.-Soviet relations: the Cold War-era relationship ended because one of its two central states ceased to exist.
End of the Cold War and U.S.-Soviet Relations (1985–1991)