The second reason that the communists won the civil war was that the Bolsheviks (communists) had better leaders. Lenin was a strong leader for all Russia and Trotsky organised the red army very efficiently. Trotsky was the chairman of the military Revolutionary Committee. Trotsky formed his new army and turned it into a feared fighting force. They controlled the industrial centres and the extensive railway networks, which enabled the reds to rush supplies and troops to any part of their front under threat. They also had the key administrative centres of Moscow and Petrograd, and were concentrated in a much smaller area than there rivals. The communists also killed the Tsar and his family so that there was no way that the Tsar would come back with the help of noble men to overthrow them. The whites had too many leaders from two many groups. They were disorganised, their geographical location made it difficult to co-operate with different armies. This brought the reason why the communists won the civil war because they were well prepared.
The third reason that the communists won the civil war was that the whites were at a disadvantaged because their troops were spread out across the country. In the northwest the forces of General Yudenich threatened Petrograd. The British assisted him. In the southwest, the threat came from General Deniken and his successor, General Wrangler. Also there was another war being fought against the poles. Anxious to seize further territory from their traditional enemy, they had invaded Russia in spring 1920. this brought the reason why the communists won the war because it made it easier for the communists to fight and win.
Another reason that the communists were able to win the civil war was because the peasants decided to join the Bolsheviks. The majority of peasants were annoyed when the whites won back land and then returned it to landlords. They did not want to go back to the Tsarist regime. Also because of the fact that some white leaders such as Kolchak were brutal and established a harsh rule over territories. General Deniken slaughtered 100,000 Jews in the Ukraine. This white terror encouraged many Russians to support the Reds. This brought the reason why the communists won the civil war because there were more people their side.
The last reason that the Communists won the civil war was that after 1919 allied support for the whites fell apart. When world war ended the allies wanted peace, so the troops left Russia. They signed the peace treaty therefore not allowing there to be anymore fighting. The troops had left Russia since they had stopped fighting and thee was no on to help back the Whites. This brought the reason why the communists won the civil war because the whites had no backup therefore allowing it to be easy for the communists to attack.
After considering all the evidence I think that the main reason was that the Bolsheviks were united in a strong ideology. I think this because there ideology of communism is what allowed the peasants to be on their side and also because they had one aim they were certain about what they were fighting about and didn’t argue.