By March 1920, it became clear that Soviet Russia would attack and invade Azerbaijan. The Soviet Bolshevik leader Vladimir Lenin said that the invasion was justified by the fact that Soviet Russia could not survive without the Baku oil fields, which was at that time the largest oil field in the world with more than half of the world's oil reserves. According to the common opinion in Moscow, Russian Bolsheviks were to "help" the Baku proletariat (workers) in overthrowing the "counter-revolutionary nationalists", meaning the government and the state of the Azerbaijan Democratic Republic.