A Tillerson Slip Offers a Peek Into Secret Planning on North Korea

WASHINGTON — Secretary of State Rex W. Tillerson let slip last week a few tantalizing details about one of the nation’s most secret military contingency plans: how the United States would try to race inside North Korea to seize its nuclear weapons if it ever saw evidence that Kim Jong-un’s government was collapsing.

For years, American diplomats have been trying to engage their Chinese counterparts in a discussion of this scenario, hoping to avoid a conflict between arriving American Special Forces — who have been practicing this operation for years — and the Chinese military, which would almost certainly pour over the border in a parallel effort.

And for years the Chinese have resisted the conversation, according to several former American officials who tried to engage them in joint planning. The Chinese feared that if news of a conversation leaked, Beijing would be seen as conspiring with the United States over plans for an eventual North Korean collapse, eroding any leverage that Beijing still held over Mr. Kim.

So it was surprising to Mr. Tillerson’s colleagues in the White House and the Pentagon when, in a talk to the Atlantic Council last week, he revealed that the Trump administration had already provided assurances to China’s leadership that if American forces landed in North Korea to search for and deactivate nuclear weapons, the troops would do their work and then retreat.

North Korea has defied past predictions of collapse, and one does not appear imminent. But if a collapse were to occur, the aftermath could present grave dangers. American officials have envisioned that North Korean officers, fearing the end of Mr. Kim’s government, might lob a nuclear weapon at South Korea or Japan as a last, desperate act — or detonate it on North Korean territory to make occupation impossible.

On Tuesday, speaking from note cards, Mr. Tillerson said at a conference on the Korea crisis that the United States and China “have had conversations about in the event that something happened — it could happen internal to North Korea; it might be nothing that we from the outside initiate — that if that unleashed some kind of instability, the most important thing to us would be securing those nuclear weapons they’ve already developed and ensuring that they — that nothing falls into the hands of people we would not want to have it.”