But seriously, why didn't communism triumph in the 20th century when things were looking so good? If the russian revolution and chinese revolution can succeed, liberating 800 million people, 1/3rd of the world's population, defeat the nazis, why couldnt we finish the final stretch? What was the fatal flaw?
A bunch of things, like the SPDs betrayal. But ultimately The Battle of Warsaw prevented the Soviets giving direct support to any revolutionary outbreak.