Mikhail Gorbachev didn't understand economics or capitalism but he was without out a doubt the most important man of peace of the 20th Century. This is not well understood but he had the military resources available to him, despite a collapsing economy, him to order a brutal and massive crackdown against protesters.
Following a coup attempt, he did not order such a crackdown but advised the Central Committee to dissolve. He resigned as general secretary and dissolved all party units within the government. Shortly afterward, the Supreme Soviet suspended all Party activities on Soviet territory. Tye Soviet Union had ended,
Also, during his reign, Gorbachev's policies of glasnost ("openness") and perestroika ("restructuring") and his reorientation of Soviet strategic aims contributed to the end of the Cold War.