The policy of containment:

It was a policy to stop the spread of communism, especially throughout Europe. We were coming out of a period of isolationism with America First'ers, etc. We were reluctant to become too involved in the affairs of the world.

But the decision was made that if we could not stop the spread of communism, the least we could do would be to contain it. That was, more or less, our policy until the collapse of the Soviet Union.

There may be lessons that can be learned in other areas, from the containment policy?