Who are the reds in World War I?

Answer 1

Sorry, but you are mistaken. the reds were not in WW1, but they were massively important during the Bolchievik Revolution and in WW2. in the Bolchievik Revolution, they were the army fighting for communism, but in WW2, Reds were a general term for the Russian army.

Answer 2

The Red Army themselves were not particularly involved in the battles of ww1. The Red Army were the Communist Party (latterly the Bolsheviks). They disagreed with war and wished to withdraw from it, and did so (in 1917) a year before the war ended. The Communists saw WW1 as a "capitalists" war and hence wanted nothing to do with it.