Answer:
Military forces became one of the largest components of peacetime spending in the Cold War. There, after World War II, America and the Soviet Union engaged in a nuclear arms race that threatened for almost 40 years to unleash a nuclear World War III.
And it was precisely that arms race that prevented that war, since the fear of both nations of the possibilities of being destroyed by the other made both decide to avoid direct confrontations. Thus, military development became a deterrent to the enemy, capable of guaranteeing peace, precisely because of the fear of the United States' power of military response.