Many countries were affected by communism after World War II. Since I can't see your map, I'll just give some examples.
Cuba- USSR supplied them with missiles to use as a defense mechanism (Cuban Missile Crisis), this was the closest the USA and the USSR came to fighting a war
Eastern European Countries- USSR took over and they became communist
The USA- Engaged in a Cold War with USSR from 1945 and until 1991
Vietnam- Vietnam War, Communists won and took control
Korea- The communists from the North tried to take over the non-communist South. They went to war and ended up splitting it in the middle (38th parallel).