Threaten, sure, but they're unable to destroy us without also assuring their own destruction. And nations will always be able to harass us cheaply. That's just

Threaten, sure, but they're unable to destroy us without also assuring their own destruction. And nations will always be able to harass us cheaply. That's just the reality of the situation and likely always will be, and will be responsible for the US being more selective about the conflicts in which it asserts itself: the Truman Doctrine, for all of its nobility, exposes the weakness of a global posture when everyone isn't panicked about global thermonuclear war: we just have to care less about things that don't impact us as much, or we'd be at war everywhere. Taking all bait would collapse the republic.