Is North Korea irrational? Or does it just pretend to be?

North Korea has given the world ample reason to ask: threats of war, occasional attacks against South Korea, eccentric leaders and wild-eyed propaganda. As its nuclear and missile programs have grown, this past week with a fifth nuclear test, that concern has grown more urgent.

But political scientists have repeatedly investigated this question and, time and again, emerged with the same answer: North Korea’s behavior, far from crazy, is all too rational.

Its belligerence, they conclude, appears calculated to maintain a weak, isolated government that would otherwise succumb to the forces of history. Its provocations introduce tremendous danger, but stave off what Pyongyang sees as the even greater threats of invasion or collapse.

Denny Roy, a political scientist, wrote in a still-cited 1994 journal article that the country’s “reputation as a ‘crazy state’” and for “reckless violence” had “worked to North Korea’s advantage,” keeping more powerful enemies at bay. But this image, he concluded, was “largely a product of misunderstanding and propaganda.”