I'm not being obtuse, I think we just have different views on how the world works.

In my view, violence, or hopefully, just the threat of violence, maintains order.

There are certain classes of people where diplomacy and pacifism just isn't going to work.

Again, the post-1945 US nuclear program is about deterrence ("peace through superior firepower"). So, in that perspective, the Peacekeeper's threat of violence... kept the peace.

The US and the Soviet Union/Russia both do not want to use nuclear weapons.

Citation: Self. Was in the nuclear program during the latter days of the Cold War and shortly thereafter.