To begin, it didn't promote "peace" as much as it promoted a "cold war" which is the whole point of the name, Cold War.
Nuclear Weapons essentially forced the US and the Soviet Union into an uncomfortable draw.
They knew they couldn't fight each other directly so they fought each other in a series of devastating proxy wars around the world.
If you give the available answers with your question you are more likely to get the right response
How were the Irish Immigrants treated when they came to America?
1. The Department of War (Henry Knox)
2. The Department of the Treasury (Alexander Hamilton)
3. The Department of the State (Thomas Jefferson)
All of them were established in 1789.