Gorbachev hoped that he could at least hold the union together in a decentralized form. However, in the eyes of the remaining CPSU conservatives, he had gone too far because his new union treaty dispersed too much of the central government's power to the republics. On August 19, 1991, one day before Gorbachev and a group of republic leaders were due to sign the union treaty, a group calling itself the State Emergency Committee attempted to seize power in Moscow. The group announced that Gorbachev was ill and had been relieved of his state post as president. Soviet Union vice president Gennadiy Yanayev was named acting president. The committee's eight members included KGB chairman Vladimir Kryuchkov, Internal Affairs Minister Pugo, Defense Minister Dmitriy Yazov, and Prime Minister Pavlov, all of whom had risen to their posts under Gorbachev.

Large public demonstrations against the coup leaders took place in Moscow and Leningrad, and divided loyalties in the defense and security establishments prevented the armed forces from crushing the resistance that Yeltsin led from Russia's parliament building. On August 21, the coup collapsed, and Gorbachev returned to Moscow.

Once back in Moscow, Gorbachev acted as if he were oblivious to the changes that had occurred in the preceding three days. As he returned to power, Gorbachev promised to purge conservatives from the CPSU. He resigned as general secretary but remained president of the Soviet Union. The coup's failure brought a series of collapses of all-union institutions. Yeltsin took control of the central broadcasting company and key economic ministries and agencies, and in November he banned the CPSU and the Russian Communist Party.

By December 1991, all of the republics had declared independence, and negotiations over a new union treaty began anew. Both the Soviet Union and the United States had recognized the independence of the Baltic republics in September. For several months after his return to Moscow, Gorbachev and his aides made futile attempts to restore stability and legitimacy to the central institutions. In November seven republics agreed to a new union treaty that would form a confederation called the Union of Sovereign States. But Ukraine was unrepresented in that group, and Yeltsin soon withdrew to seek additional advantages for Russia. In the absence of the CPSU, there was no way to keep the Soviet Union together. From Yeltsin's perspective, Russia's participation in another union would be senseless because inevitably Russia would assume responsibility for the increasingly severe economic woes of the other republics.

On December 8, Yeltsin and the leaders of Belarus (which adopted that name in August 1991) and Ukraine met at Minsk, the capital of Belarus, where they created the Commonwealth of Independent States (CIS--see Glossary) and annulled the 1922 union treaty that had established the Soviet Union. Another signing ceremony was held in Alma-Ata on December 21 to expand the CIS to include the five republics of Central Asia, Armenia, and Azerbaijan. Georgia did not join until 1993; the three Baltic republics never joined. On December 25, 1991, the Soviet Union ceased to exist. Exactly six years after Gorbachev had appointed Boris Yeltsin to run the Moscow city committee of the party, Yeltsin now was president of the largest successor state to the Soviet Union.