North Korea watched on in caution and then horror as the Libyan leader accepted a U.S. deal to dismantle his nuclear regime in return for sanctions relief, because it turns out there was no lifetime guarantee: In 2011 he was killed by NATO-backed rebels, with ignominious images of his bloodied body going viral on social media.

For Kim, the episode highlights the perils of accepting assurances from the U.S. in return for handing over his weapons.

So the championing by U.S. President Donald Trump's National Security Adviser John Bolton of a "Libyan model" for North Korean disarmament was never going to go down well. It's just weeks before Trump and Kim are due to meet in Singapore. Meanwhile the U.S. and South Korea are carrying out annual military drills that tend to upset Pyongyang.