It’s possible that the good cop-bad cop routine is deliberate. Tillerson says that the State Department has “a couple of direct channels to Pyongyang” for humanitarian purposes and is hoping for a “peaceful resolution”; Trump tweets “Save your energy Rex, we’ll do what has to be done!” The Wall Street Journal reports Sunday night that the U.S. is stepping up its economic pressure campaign to force Kim to the table; the following morning, Trump tweets that “Policy didn’t work!”

But that doesn’t mean it’s smart strategy. While the United Nations passed a new round of sanctions against North Korea with the hope that Kim will decide the cost of nuclear weapons is too steep, Trump’s apocalyptic threats are a constant reminder that those weapons may provide the only effective deterrent against invasion. When asked about giving up their nuclear program, “North Koreans invariably mention the former Libyan leader Muammar Qaddafi,” writes The New Yorker’s Evan Osnos, who recently returned from a trip to Pyongyang. Qaddafi was persuaded to surrender his cache of nuclear, biological, and chemical weapons; eight years later, he was overthrown with the help of U.S. and NATO forces, and murdered by rebels.

While Trump seems to think that he can scare Kim into disarmament, his tweeting is likely having the opposite effect. New York Times columnist Nicholas Kristof, who also recently toured the North Korean capital, returned to the United States convinced that Kim is not only preparing for war, but that his people believe they can survive a nuclear strike. Senator Bob Corker told the Times on Sunday that Trump’s tweets are putting the United States “on the path to World War III.”

Tillerson’s spokesman, R.C. Hammond, suggested that the president “has a strategy” and that he is putting “different tools . . . into play to help that strategy move forward.” Trump, as Axios has reported, wants to be seen around the world as a “crazy guy.” But insiders tell me that Tillerson’s credibility has been destroyed by Trump, leaving him virtually powerless to negotiate on behalf of the president. “The tweets undercut any conversation the secretary is having while visiting a key country, China, on the [North Korea] issue,” said one top career foreign-service officer who left the State Department earlier this year.

Intelligence experts argue that Kim isn’t seeking war with the U.S., but is acting rationally to deter a potential invasion. “Kim’s long-term goal is to come to some sort of big power agreement with the U.S. and to remove U.S. presence from the peninsula,” Yong Suk Lee, deputy assistant director of the C.I.A.’s Korea Mission Center, said at a conference, CNN reports. Others quietly concede that it is likely impossible to prevent North Korea from becoming a nuclear power, and are already strategizing ways to isolate and contain the Kim regime rather than launch a pre-emptive strike that would almost certainly result in unacceptable mass casualties on both sides of the demilitarized zone.

“There’s no military solution [to North Korea’s nuclear threats], forget it,” Steve Bannon, Trump’s former White House chief strategist, said in an August interview. “Until somebody solves the part of the equation that shows me that 10 million people in Seoul don’t die in the first 30 minutes from conventional weapons, I don’t know what you’re talking about, there’s no military solution here, they got us.” The fear is that Trump’s brinkmanship could lead to a miscalculation, on either side of the conflict, that would result in an accidental war. “We could stumble into something,” Ambassador Joseph R. DeTrani, who previously served as the special envoy for six-party talks with North Korea at the State Department, told CNN. “There is a sense that North Korea is unpredictable if put into a corner.”