[The] trip calls to mind William J. Dobson's concept of "the dictator's learning curve" — the idea that successful autocracies (and North Korea certainly qualifies) can adapt to prevailing realities and challenges in order to further entrench the existing system.

He cites humanitarian aid like the UN's World Food Program as an example:

WFP aid can even be thought of as a kind of unearned subsidy — or as a subsidy that the North Korean government was able to extract through its continued bad behavior. After all, the estimated $3 billion to $4 billion North Korea has spent on its missile program over the past two years could easily have resolved the country's food security problems. Pyongyang's arrangement with the WFP gives the North Korean government leverage over an international community eager to alleviate large-scale human suffering, while freeing its resources for projects that arguably prop up the regime and destabilize the southeast Asian security environment. The less North Korea cares about solving a chronic and man-made food security crisis, the more the international community feels compelled to disconnect political and humanitarian concerns in dealing with the Hermit Kingdom.