Why did Socialism work in the USSR but not in China?
Soviet Russia and the USSR essentially had a fully socialized, state run economy from the revolution in 1917 to it's collapse in 1991. Despite small reforms such as the New Economic Policy from 1921-28, the Kosygin Reforms in 1965 and Perestroika from 1985-91, the state owned and controlled almost all industry. Under a socialist economy, it went from a borderline medieval agrarian society to a space faring, industrialised superpower. The history and development of the USSR is socialism's greatest success story.
In China, things went differently. China implemented a fully socialist economy after the founding of the People's Republic of China. However, socialism in China was less than succesful. Mao attempted to rapidly industrialize the economy in the Great Leap Forward from 1958-62, which failed and led to millions of people starving to death. By Mao's death in 1976, the Chinese economy was in a drastic state, and poverty was rampant. However in 1978, the new leader Deng Xiaoping implemented massive economic reforms, which allowed private, capitalist investment. This led to the greatest economic success story in all of human history, with the standard of living rising massively in the decades since. China is now an advanced, industrialised state, which is on the way to becoming a world superpower.
So my question is this: why did socialist, planned economics succeed in industralising and modernising the USSR, while it failed in China, which had mass famines under socialism and only industrialised after capitalist reforms were implemented?