Randall Parker argues  that China’s increasing wealth will soon enable significant numbers of Chinese men to buy, or otherwise to attract, women from impoverished North Korea as wives. If this predicted large net export of women from North Korea to China actually comes to pass, North Korean men will grow even more belligerent toward China.
Parker’s sensible prediction is not unqualified; it will come to pass, he says, “unless radical changes happen to North Korea’s economy.” Such change is unlikely – but not out of the question. See this story  from Sunday’s Washington Post, describing a small-scale experiment with markets now underway in North Korea.
I thank Tyler Cowen  for the reference to Randall Parker’s post, and to my wife, Karol, for pointing out the story in the Post.