North Korea's leader Kim Jong Un attends a meeting of Korean People's Army (KPA) battalion commanders and political instructors in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 5, 2014. (Kcna/Reuters)

DECIPHERING THE motives behind North Korea’s behavior is inevitably a matter of guesswork. Still, it’s not hard to discern a couple of reasons why the reclusive Stalinist regime would have decided to release two Americans it had sentenced to hard labor just before President Obama arrived in neighboring China for an Asian summit meeting.

One is familiar: North Korea is hoping to draw the Obama administration back into negotiations about a normalization of relations. In the past, Pyongyang has used such charm offensives, along with promises to dismantle its nuclear weapons arsenal, to extract economic and political concessions from the United States and its allies. Invariably it has cheated on its commitments and then abruptly reverted to hostility and provocations.

In this instance, the regime of Kim Jong Un is not even suggesting that it could disarm. Instead, its goal seems to be to induce the United States to abandon that goal. The Post’s Anna Fifield reported that a senior North Korean official dispatched to Europe last month told officials that the only basis for U.S.-North Korean dialogue would be as “one nuclear state to another.” By releasing prisoners Kenneth Bae and Matthew Todd Miller, the regime may be hoping to induce Chinese President Xi Jinping to put pressure on Mr. Obama to break a two-year hiatus in formal negotiations without more substantive concessions.

Fortunately, Mr. Obama appears resistant to engaging with the North on its terms. Administration officials say the U.S. position remains that Pyongyang must take concrete steps toward disarmament for a diplomatic process to resume. Though the Kim regime recently has reached out to Japan and South Korea in addition to Europe and the United States, there’s no evidence it is even considering such concessions.

Another plausible explanation for the release of U.S. prisoners is that it was a purely defensive act. Diplomats in contact with the North say it has become genuinely concerned about a United Nations investigation of its appalling human rights abuses and an incipient movement to refer Mr. Kim and other top leaders to the International Criminal Court for prosecution. That call was made just two weeks ago by Marzuki Darusman, the U.N. special rapporteur on North Korean human rights, who said it was time to take action against the regime “to a new level” given its “continued state of denial of [its] widespread, grave and systematic human rights violations and crimes against humanity.”

A vote by the U.N. Security Council to refer North Korea to the court could be blocked by China or Russia. Nevertheless, the Obama administration should press for one — and dare Beijing or Moscow to shield a regime that, according to the U.N. investigation, is subjecting 80,000 to 120,000 political prisoners to horrific treatment. If pressure on human rights explains North Korea’s recent actions, that is another reason to step it up.