In relations with the Soviet Union, President Reagan's declared policy was one of peace through strength. Rooted in the Cold War tradition, he was determined to stand firm in dealing with the country he termed the "evil empire." Two events increased U.S.-Soviet tensions: the suppression of the Solidarity labor movement in Poland in December 1981, and the destruction of an off-course civilian airliner, Korean Airlines Flight 007, by a Soviet jet fighter on September 1, 1983. The United States also condemned the continuing Soviet occupation of Afghanistan and provided aid to the mujahidin resistance there.  

In Reagan's first term, his administration spent unprecedented sums for a massive defense buildup, including the placement of intermediate-range nuclear missiles in Europe to counter Soviet deployments of similar missiles. And on March 23, 1983, in one of the most hotly debated policy decisions of his presidency, Reagan announced the Strategic Defense Initiative (SDI) research program to explore advanced technologies, such as lasers and high-energy projectiles, to defend against intercontinental ballistic missiles. Although many scientists questioned the technological feasibility of SDI and economists pointed to the extraordinary sums of money involved, the administration pressed ahead with the project.  

After reelection in 1984, Reagan softened his rigid position on arms control. For its part, Moscow was amenable to agreement, in part because the Soviet economy was incapable of sustaining the level of expenditures necessary to compete with the U.S. defense build-up. In November 1985, Reagan held a summit meeting with the new Soviet leader, Mikhail Gorbachev, in Geneva. They agreed in principle to seek 50-percent reductions in strategic offensive nuclear arms as well as an interim agreement on intermediate-range nuclear forces. In December 1987, President Reagan and General Secretary Gorbachev signed the Intermediate-Range Nuclear Forces (INF) Treaty providing for the destruction of a whole category of nuclear weapons.