During the Cold War, what was one main concern of the United States?

What does this answer mean?

During the Cold War, two main concerns of the United States were communism and nuclear war. USCIS accepts either answer.

Communism is a political and economic system in which the government controls the economy and, under the Soviet Union, one party held power. The United States worked to limit communism's spread around the world, a policy often called containment. That concern is also the answer to why the United States entered the Korean War and the Vietnam War.

Nuclear war was the other great fear. Both the United States and the Soviet Union built large nuclear arsenals in an arms race, and the world came closest to nuclear war during the Cuban missile crisis in 1962. Later, the two countries signed agreements to limit nuclear weapons, including a 1987 treaty that eliminated an entire class of missiles.

The Cold War ended when the Soviet Union dissolved in 1991.

At the interview, say "communism" or "nuclear war."