North Korea has the bomb and hasn't been bombed at all. It's a great deterrent. Now look at Ukraine, which gave up its nukes in exchange for promises of security, and how those were totally violated by Russia.
North Korea isn't bombed because they have artillery directly against the head of South Korea. That's the reason they were allowed to get the bomb in the first place.
is a client state of China, and it also possess a massive array of conventional artillery in range of Seoul. And since the Korean War, which we now know conclusively that NK started, almost every overt act of aggression between the two Koreas has been perpetrated by the North against the South, e.g.: https://en.wikipedia.org/wiki/Korean_Air_Flight_858
