I remember hearing army Gen Bill Livesay (former commander of U.S. Forces Korea) say that the toughest thing about dealing with the North Koreans was you just couldn't ascribe any rationality to their actions. Livesay is a shrewd thinker who hides behind a southern good-ole boy facade, so it is quite an admission on his part that he could never figure the North Koreans out. They do not maneuver on the world stage in anyway similar to their communist forebears, such as the Soviets or the Red Chinese. As a long time cold warrior, Livesay and the other strategists of the cold war era were used to anticipating, or at least understanding, what the the Soviets and Chinese were up to. There was almost always method to their madness. But the lessons they gleaned from dealing with the two communist great powers proved useless against the North Koreans.
B.R. Myers, a professor in South Korea, recently offered a very unique perspective on why the North Koreans proved so inscrutable to the West, and even to their supposed allies, China, and Russia. His talk featured on C-Span's BookTV (BookTV - I freely admit I am addicted), was quite illuminating for those who've had to concern themselves with the situation.
He notes chiefly that North Korea is primarily a racist, nationalist regime built on militarism. It is communist only secondarily. They consider themselves to be a pure race, plagued by jealous, evil outsiders, meaning chiefly the U.S. and other westerners, but also including their Asian neighbors, the Japanese and Chinese. His observations about the matronly characterization of the regime in its own propaganda were completely new to me. And I have quite a bit of exposure to American strategic thinking on North Korea over the last couple decades. For anyone interested in the Korean Peninsula, his presentation is worth the time. I definitely intend to read his book.