Well, that explains it.
The "bedroom nations" didn't have to worry about the Soviets. Someone else was carrying the load for them.
Your starry-eyed view of the U.N. is typical--and completely immune to the actual behavior of that agency in foreign threat issues in past decades.
In short, the U.N. is like a police department largely manned by local Mafia members.
Or maybe you never noticed which side they almost always took during the later years of the Cold War.