is spam more important than a smart guess? Korea, like any Korea? it's possible, just that it haven't been invaded from even before submarines existed. Think of ways that american submarines could use secretly so that communists couldn't know, maybe anti-communist wars? how many were there? What kind of allies were near this communist threat?
NHL found a passage used by submarines because of the depth of the waters, just link with the clues and you'll find it, not many countries in the world got invaded with the support of USA that USA didn't got involved directly.
clue:the communist party of this country won after a civil war, (guess what, this civil war was secretly funded by USA, something like the Al-Qaeda), and then the country got invaded by a third nation (supported by USA) (all this because of communism)
