Every political doctrine or ideology has a certain political idiom, which tends to play a central character in how the followers of that ideology carry out their political activities.
With due respect for the believers in Communism, I feel Violence is the perennial political idiom of Communism. It seems Communists’ excessive obsession with "struggle" always makes them opt for ultra-aggressive steps, even when there is room for other options. This probably explains the bloodshed on almost every occasion when radical Communists have ceased power in a country. Communism has always tended to glorify "Revolution" rather than favoring the more acceptable "Evolution", while overlooking this fact that "Revolution" entails conflict.
This post is not aimed at maligning Communism, which is certainly one of the most notable political theories that the human civilization has ever come across. It is rather an observation by a very ordinary person, who otherwise very much identifies with some of the key objectives of Communism (such as a classless society).