What countries were communist during world war ii?

During World War II, the primary communist country was the Soviet Union, which played a significant role in the Allied powers' efforts against the Axis. Additionally, other countries had communist movements or parties, but they were not fully communist states at the time. Notably, China had a significant communist faction, the Chinese Communist Party, led by Mao Zedong, although it was not in control of the entire country until after the war. Other regions, like Eastern Europe, had communist parties that gained prominence during the war, but they became dominant only post-war.