A Cold Warrior is a person who was actively involved in the conflicts between the Soviet Union and the United States during the Cold War era.
Kennedy would be considered a cold warrior due to his interactions with the Soviet Union. One of the most famous examples is the Cuban Missile Crisis. This conflict that took place in October 1962 was based around the Soviet Union placing missives in Cuba. This was the closest the world ever came to nuclear war. However the US and Soviet Union came to a deal.
Nixon would be considered a cold warrior as well because of his role in combating domestic communism during the 1950’s. He heavily influenced the House Un American Activities Committee that questioned American citizens and their ties to the Soviet Union/communism.