With the background of the build-up of tension between the Soviet Union and the United States, NATO decided, under the impetus of the Reagan presidency, to deploy Pershing II and cruise missiles in Western Europe, primarily West Germany. These missiles were theatre nuclear weapons intended to strike targets on the battlefield if the Soviets invaded West Germany. Yet support for the deployment was wavering and many doubted whether the push for deployment could be sustained. On 1 September 1983, the Soviet Union shot down a Korean passenger airliner when it crossed into Soviet airspace â€“ an act which Reagan characterized as a "massacre". The barbarity of this act, as the U.S. and indeed the world understood it, galvanized support for the deployment â€“ which stood in place until the later accords between Reagan and Mikhael Gorbachev.