During the Korean “police action,” US strategic bombing of the North killed an estimated (by the US) one fifth of the population.
One might argue that the populations of Germany, or Japan, or even North Vietnam might have a similar grievance. But there’s a crucial difference: the Korean conflict never officially ended, one way or the other.
For Germany and Japan, they lost, big-time. They were occupied. Their history was written by the victors, and with admission (reluctant or otherwise) of the crimes and aggression of the losers that triggered and perpetuated the conflict they eventually lost.
For North Vietnam, the war brought eventual victory over the South and, by proxy, the Americans.
For North Korea, though, the war never ended — and, yes, this is where the tyranny and lies come into play, as the Kim regime has endlessly beat the drum for six decades that the Americans (and the South) started the war, that the North (handwaving China) beat them back with horrific (true) losses, but that the Americans (and the South) might attack again at any time.
In such a climate, the loss of 20% of the population, and the economic devastation that resulted, makes the North Koreans understandably anti-American — and, given that bombing, not without justification, regardless of who started the war or the zaniness and homicidal tyranny of their government ever since that time.
The U.S. war crime North Korea won’t forget – The Washington Post
Pyongyang’s hatred of America is partly based on U.S. actions during the Korean War.