WASHINGTON — When President Donald Trump gave a fiery campaign speech in Huntsville, Alabama, on Friday evening, he drew a rapturous roar by ridiculing Kim Jong Un, the North Korean leader, as "Little Rocket Man."
Among diplomats and national security specialists, the reaction was decidedly different. After Trump repeated his taunt in a tweet late Saturday and threatened that Kim and his foreign minister "won't be around much longer" if they continue their invective against the United States, reactions ranged from nervous disbelief to sheer terror.
Trump's willingness to casually threaten to annihilate a nuclear-armed foe was yet another reminder of the steep risks inherent in his brute-force approach to diplomacy. His strengths as a politician — the ability to appeal in a visceral way to the impulses of ordinary citizens — are a difficult fit for the meticulous calculations that his own advisers concede are crucial in dealing with Pyongyang.
The disconnect has led to a deep uncertainty about whether Trump is all talk or actually intends to act. The ambiguity could be strategic, part of an effort to intimidate Kim and keep him guessing. Or it could reflect a rash impulse by a leader with little foreign policy experience to vent his anger and stoke his supporters' enthusiasm.
His new chief of staff and his national security team have tried to rein in his more incendiary provocations, fearing that their efforts could backfire with a president who bridles at any effort to control him. What remains unclear — and the source of much of the anxiety in and out of the government and on both sides of the Pacific — is whether they would step in to prevent the president from taking the kind of drastic action that matches his words, if they believed it was imminent.
Veterans of diplomacy and national security and specialists on North Korea fear that, whatever their intended result, Trump's increasingly bellicose threats and public insults of the famously thin-skinned Kim could cause the United States to careen into a nuclear confrontation driven by personal animosity and bravado.
"It does matter, because you don't want to get to a situation where North Korea fundamentally miscalculates that an attack is coming," said Sue Mi Terry, a former intelligence and National Security Council specialist who is now a senior adviser for Korea at Bower Group Asia. "It could lead us to stumble into a war that nobody wants."
And while his bombast may be a thrill to Trump's core supporters, there is evidence that the broader U.S. public does not trust the president to deal with North Korea, and is deeply opposed to the kind of pre-emptive military strike he has seemed eager to threaten.
A new Washington Post-ABC News poll found that 37 percent of adults trust Trump "a great deal" or "a good amount" to responsibly handle the situation with North Korea, while 42 percent trust him "not at all." By contrast, 72 percent trust U.S. military leaders, who have largely avoided combative language on North Korea even as they have said publicly that a military option is possible.
Two-thirds of respondents opposed launching a pre-emptive attack against North Korea, while about three-quarters supported using tougher economic sanctions on Pyongyang as a way of pressuring the country to surrender its nuclear arsenal.
Some senior administration officials acknowledge privately that Trump's rhetoric on North Korea is not helpful, although they question whether it will alter the discussion, given how far Kim has come in his quest to develop a nuclear weapon that could reach the United States.
The three current and retired generals advising Trump — Jim Mattis, the defense secretary; Lt. Gen. H.R. McMaster, his national security adviser; and John F. Kelly, his chief of staff — as well as Rex Tillerson, the secretary of state, have all chosen their words on North Korea more carefully, emphasizing the role of diplomacy and the grave stakes of any military confrontation.
"All three of the generals fully realize the carnage that would result from a war on the Korean Peninsula," James G. Stavridis, the former NATO commander and current dean of the Fletcher School of Law and Diplomacy at Tufts University, said on Sunday.
"Knowing each of them personally, I am certain they are counseling operational caution, measured public commentary and building a coalition approach to dealing with Kim Jong Un," Stavridis, a retired admiral, said in an email. "But controlling President Trump seems incredibly difficult. Let's hope they are not engaged in mission impossible, because the stakes are so high."
Christopher R. Hill, a former ambassador to South Korea who served Republican and Democratic presidents, argued that the comments could badly undercut Trump's ability to find a peaceful solution to the dispute, playing into Kim's characterization of the United States as an evil nation bent on North Korea's destruction and relieving pressure on the Chinese to do more to curb Pyongyang.
"The comments give the world the sense that he is increasingly unhinged and unreliable," said Hill, the dean of the Josef Korbel School of International Studies at the University of Denver.
Hill, who as envoy to South Korea under George W. Bush was the last American to hold formal talks with the government in Pyongyang, said he and Condoleezza Rice, then the secretary of state, routinely advised Bush to "avoid the personal invectives," because "they never help."
"My sense from four years of those talks is that getting personal is not helpful," Hill said. "Who could be telling Trump otherwise?"
Yet current and former senior officials said it was clear that Trump would continue his brinkmanship, particularly his belligerent tweets, no matter what his advisers do or say. One former administration official, who spoke on the condition of anonymity to discuss internal policy workings, said nobody, including Kelly, could control the president's social media utterances, despite what his military advisers thought about them.
The tweets most likely have forced Mattis and Gen. Joseph F. Dunford Jr., the chairman of the Joint Chiefs of Staff, as well as other national security officials, to spend a significant amount of time on the phone reassuring counterparts about Trump's intentions.
Last week, Trump coined his mocking nickname for Kim on Twitter and insisted on including it in his maiden speech to the United Nations General Assembly. "Rocket Man," he said, "is on a suicide mission for himself and for his regime," which may leave the United States "no choice than to totally destroy North Korea."
The speech drew audible gasps from the diplomats and national security officials in the General Assembly hall, as well as an angry response from Kim himself, who called Trump a "mentally deranged U.S. dotard." A few days later, a capacity crowd at the Von Braun Center in Huntsville delighted in Trump's warlike language, cheering as he renewed his threats and added a dig at Kim's stature.
[A short history of 'dotard,' the arcane insult Kim Jong Un used in his threat against Trump]
"He should have been handled a long time ago," Trump said, "but I'm going to handle it because we have to handle it: Little Rocket Man."
"I'm sure he's listening, because he watches every word," Trump added. "He's watching us like he never watched anybody before, that I can tell you."
The president appeared to be right about that. On Saturday, Foreign Minister Ri Yong Ho of North Korea said in a speech at the U.N. that the president's threats were "making our rocket's visit to the entire U.S. mainland inevitable all the more."
That is what appeared to have prompted the nighttime tweet from Trump, who spent the weekend at his Bedminster, New Jersey, golf resort. "If he echoes thoughts of Little Rocket Man," Trump wrote of Ri, "they won't be around much longer!"
Terry said such menacing talk could put Trump into a box. "Trump is limiting our own options by behaving and speaking like this, because now we either have to act, which really is unthinkable, or we're going to look like a paper tiger because we can't act," she said. "Internationally, we look foolish, and now he has made it extremely personal, so Kim Jong Un cannot back down. It's reckless."
Some of Trump's allies argue that his behavior is strategic, a way of telegraphing to North Korea — and to its primary patron, China — that the United States is taking a tougher line under this administration. There may be wisdom, they argue, in spurring fear and confusion in the mind of a leader who frequently relies on both.
"We're dealing with somebody that we'll figure out," Trump said at the rally on Friday. "He may be smart, he may be strategic — and he may be totally crazy."
Eric Schmitt contributed reporting.