North Korean policy?

[Anomalocaris]

It's not an issue of alternatives though. Ideally we stick by our friends regardless of what position they find themselves in. That wealth (and that mic) has been generated in very large part by collaboration with the US, wouldn't you say?

That's ignoring that we don't maintain a presence in S. Korea solely for the purpose of standing down N. Korea. It keeps troops on station in the region, for a quick response.

It is very unlikely American troops stationed in South Korea could ever be quickly redeployed to respond to any crisis outside of Korea. It is also extremely unlikely South Korea would permit American forces in South Korea to conduct operations from Korean soil against any other power outside Korea. American presence in South Korea is widely disliked and barely tolerated, and only continue because South Korea does not wish to let Japan dominate America's perception of who matters to American interest in East Asia. If given a choice, South Korea would rather ally with China to gang up on Japan than to join any effort by either the US or Japan to contain China. It is Korea's ambition to achieve unification on Korean penninsula and then leverage its favorable demographics and far faster rates of economic growth to supplant Japan as the premier military and economic power in East Asia next to China before middle of the 20th china.