effective verification system. Meanwhile, in December the INF Treaty between the United States and the Soviet Union was signed, effectively allowing mutual inspections. During the May–June 1988 Moscow Summit, US President Ronald Reagan and General Secretary Gorbachev emphasized the importance of stability and security in Europe, specifically calling for data exchange, verification of these data, and then reductions. In December Gorbachev announced at the United Nations a unilateral withdrawal of 50,000 troops from Eastern Europe, and demobilization of 500,000 Soviet troops. CFE negotiations In January 1989, NATO and the Warsaw Treaty members produced the Mandate for the Negotiation on Conventional Armed Forces in Europe. The mandate set out objectives for the CFE Treaty and established negotiating principles, and formal negotiations began on March 9, 1989 in Vienna. When US President George H. W. Bush and France's President François Mitterrand met in May, Bush announced the acceptance of reductions of combat aircraft and helicopters. He also proposed a ceiling of 275,000 personnel stationed in Europe by the US and Soviet Union. Bush's proposal was formally adopted during the 1989 Brussels NATO summit and subsequently presented in Vienna. In July, the 1989 Polish legislative election held in accord with the Polish Round Table Agreement resulted in the appointment on 24 August 1989 of a first non-communist Prime Minister considered an effective end of communist rule in Poland, followed in November by the fall of Berlin Wall in Germany. In the following months revolutions broke out in Hungary, Czechoslovakia, Romania, Bulgaria and Albania. Bush and Gorbachev agreed to speed up arms control and economic negotiations. Bush proposed even steeper reductions, and the Soviet Union negotiated and concluded troop withdrawal agreements with Warsaw Treaty states. The ensuing German reunification would lead to the Treaty on the Final Settlement with Respect to Germany linked to the CFE treaty by specifying that certain military limits imposed on Germany would come into force upon the conclusion of the CFE Treaty. The text of the treaty was approved by the 22 negotiating states on 15 November 1990 in Vienna. The Vienna Document on confidence- and security-building measures, also first adopted in 1990, and the CFE Treaty, were seen as parallel peace process components by the Organization for Security and Co-operation in Europe (OSCE). 1990 signature ceremony in Paris The Treaty was signed in Paris on November 19, 1990 by 22 countries. These were divided into two groups: the