world war 2 and the korean war made American manufacturing jobs leave to japan and south korea, since they allowed American military bases on their land.
American military bases that do not protect our homeland and being world policeman is expensive, since nuclear weapons do not allow empires any longer.
however you are wrong that north korea is being provoked into attacking thousands of American troops in japan and south korea, they have a choice to accept they are weaker in a world ruled by might makes right.
their destruction will make America richer, and able to pursue happiness as its founding fathers intended for it.