In power for barely more than a year, North Korean leader Kim Jong Un has adhered overwhelmingly to the policies of his father, using a familiar mix of internal repression and nuclear showmanship while all but dashing hopes he would emerge as a Deng Xiaoping-style reformer.

Although analysts caution that Kim can still change course, the apparent status quo on policy carries dark implications, extending — perhaps for a generation to come — a government that relishes isolation, threatens its neighbors, values weapons over food for its people and keeps roughly 1 in every 120 of its citizens in gulags.

Tuesday's underground nuclear detonation, coupled with a recent long-range rocket launch and a string of fierce rhetoric toward the United States, represents a clear borrowing from the playbook of Kim Jong Il. And analysts say that the young Kim, believed to be 30, has good reason to embrace his father's cold-blooded strategies.