How did Gorbachev's reforms lead to the breakup of the Soviet Union?

The break up of the totalitarian U.S.S.R. into 15 democratic states is one of the most important events in modern history. By the time Mikhail Gorbachev was appointed Secretary of the Communist Party of the Soviet Union in 1985 the U.S.S.R. was already on the verge of breaking up: the economy was in a very bad shape and three senior party leaders had died in three years creating a political vacuum. His three important reforms were, glasnost, perestroika and democratisation.

Glasnost or 'openness' led to the rewriting of Soviet history and the previously great leaders were unmasked for whom they really were.

Perestroika or 'restructuring' refers to Gorbachev's failed attempts to revive the ailing Soviet economy. When he took over, the economy was in serious trouble with shortages of even the most basic items like bread but Gorbachev did not want to radically change the way the Soviet economy worked. His half hearted attempts at economic reform were a failure and he became very unpopular.

His process of Democratization resulted in power being shifted from the Politburo to the people themselves. In March 1989, the first elections since 1917 were held in Russia.

All these reforms resulted in the complete dissolution of the U.S.S.R.