I think the South Koreans are extremely grateful not to be part of the North. That's a terrible example for you to pick.
Iraq...well they might not be too happy but I bet their neighbors insisted on Hussein being sorted out.
etc etc.
It isn't noble, it's practical. The US protects countries that supply oil to it. Korea turns out to be an extremely important ally and part of the world economy....etc.
I lot of Iraqis are very happy the US intervened, even though IMO it was a terrible move for many reasons (starting with the BS about WMD). The sunnis that supported Saddam didn't like it of course, but the other groups he oppressed were happy about the US invasion.
Iraq...well they might not be too happy but I bet their neighbors insisted on Hussein being sorted out.
etc etc.
It isn't noble, it's practical. The US protects countries that supply oil to it. Korea turns out to be an extremely important ally and part of the world economy....etc.