What leaders tried to reform the Soviet Union?

Several leaders attempted to reform the Soviet Union, most notably Mikhail Gorbachev in the 1980s. He introduced policies such as glasnost (openness) and perestroika (restructuring) to promote transparency and economic reform. Other figures, like Nikita Khrushchev, also sought reform through de-Stalinization and attempts to shift towards a more consumer-oriented economy. However, these efforts often faced significant resistance and ultimately contributed to the dissolution of the Soviet Union in 1991.