I think you are off tangent on the rationality part. The North Korean regime has survived this long because it is rational. It has perfected the art of brinkmanship by ratcheting tensions and then stepping back after gaining concessions. If they truly thought they were invincible, they would have attempted an invasion long ago.
You can't be serious?? North Korea? "Rational"?
It's survived because it was a client state of China. But it's survived mostly because the US Government and State Depts. were infested by Commie sympathizers back in the 50s and 60s, and because the cowardly policies of both Bubba Klintoon and George W. Bush prevented North Korea from starving, and enabled its development of nuke capabilities.
Idiots and traitors.
Good point. However, the old man is getting senile, and his son is plain nuts. The generals in North Korea are nuts, too.
I think the “game” has changed. This isn’t brinksmanship. This is insanity.