A probable answer for your question is that the United States needed to develop more and better weapons to prevent an attack.
Explanation:
In the Cold War, once both the United States and the Soviet Union had atomic weapons, the two sides were in a tense standoff. Each side developed a larger and larger arsenal of weapons, knowing that provoking a war would mean mutually assured destruction. Having more weapons and defense spending, in the eyes of military planners, was a way of preventing the other side from daring an attack.
John Foster Dulles, Secretary of State under President Eisenhower, pushed for this kind of approach. Dulles wasn't afraid to threaten massive retaliation against communist enemy countries as a way of intimidating them and preventing the communist side from pursuing any sort of attack on the United States.