Is the US running an empire?

[carl]

Who would you contain?

Any hostile or potentially hostile country that could deploy a powerful navy.

It seems less about containment to me than to an effort to respond to perceived threats wherever they emerge... not so much about establishing a clear perimeter as a global game of whack-a-mole.

Why are they threats? If you are trying to maintain a perimeter, people will try to penetrate it at various places and you are going to end up playing whack-a-mole.

Either way, as you say, none of this has any relation to empire, and thus it belongs on another thread.

David can handle that when he will.