Drug dealers shooting cops is a completely rational defensive response to police aggression. Saying that does not mean the drug dealers are good people, and saying that does not mean the police actions provoking the response are appropriate, either. It's quite possible for both sides of a conflict to be in the wrong.
North Korea is one of the worlds largest heroin dealers so this isn't even a bad analogy.
And the War on Drugs, black-and-white, shoot first, pretends to be about ethics but really about profits, is a pretty good analogy for US foreign policy in general, too.
The US didn't just participate in the Korean War. US troops massacred refugees, intentionally targeted civilians and civilian infrastructure, and, well, there were some rapes, too. North Koreans do not like the US and given their only recent interaction with the US they have very good reason not to.
The only way to stop North Korea would be to invade North Korea, and the US doesn't have enough money or forces to do that without compromising US national defence.
The last Korean War spread the US so thin it was almost a disaster, despite the WW2 + Cold War buildup and conscription. With US forces already occupying two hostile countries under Bush there was really nothing he could do about it.
I do not think the Kim's are sophisticated strategists by any stretch, but it still wouldn't surprise me if I heard that they intentionally delayed their nuclear weapons program until the US got themselves snarled in another stupid, expensive Forever War.
Good news, then: North Korea has approximately a trillion conventional and chemical artillery shells pointed into South Korea, so if the regime collapsed South Korea wouldn't need to worry about supporting any refugees, because there wouldn't be a South Korea anymore.
China, though, for sure. Also the North Koreans would prefer their current government to the idea of US boots on their soil. Probably a bunch of Swiss bankers want to keep the Kim's around, too. idk.