WASHINGTON — It was only a few hours after his secretary of state cracked open the door on Thursday to negotiating with the North Koreans that President Trump stepped in with exactly the kind of martial-sounding threats against the country that the White House, until now, had carefully avoided.
Viewed in the most charitable light, Mr. Trump was, in his own nondiplomatic way, building pressure to force the North into a freeze of its nuclear and missile tests, the first step toward resuming the kind of negotiations that Secretary of State Rex W. Tillerson had spoken of earlier in the day. Or, perhaps, he was engaging in a bit of the “madman theory” that he and many of his aides reportedly admire about President Richard M. Nixon, who tried to convince Ho Chi Minh, the wily North Vietnamese leader, that he might be crazy enough to drop “the bomb” if they could not find a way to end the Vietnam War.
But the most likely explanation is that Mr. Trump, who until now has largely avoided taking the bait that the North Korean propaganda machine churns out with its own warnings of imminent war, simply reverted to an old habit: sounding as tough as the other guy. The problem is that it clashes with the message his administration has been sending out in recent days that no pre-emptive strikes are planned and that there is plenty of time and space for diplomacy. Mr. Trump’s aides talk of an “integrated strategy” of escalating military and economic pressure to force diplomatic engagement.
The objective, Adm. Harry B. Harris Jr., who heads the United States Pacific Command, told Congress this week, is to “bring Kim Jong-un to his senses, not to his knees,” a reference to the insecure if absolute leader of North Korea.
That also seemed to be Mr. Tillerson’s message. In an interview with NPR, he tried to sound reassuring, saying: “We do not seek a collapse of the regime. We do not seek an accelerated reunification of the peninsula. We seek a denuclearized Korean Peninsula.” He even raised at least the possibility of direct talks.
Mr. Trump missed an opportunity to reinforce that effort to reassure the North Koreans that the United States is not looking to topple their leader. Instead, his message could be taken as the opposite.
Mr. Trump’s negotiating strategy has often involved the taking of an extreme position, hoping that the other actor in a test of wills will be thrown off enough to move in his direction. That is one thing when it means threatening to pull out of Nafta, the gambit Mr. Trump floated, then retreated from, this week. But it can be a far riskier bet when exchanging signals with Mr. Kim, who has survived so far — like his father and grandfather before him — by employing a similar playbook of extreme rhetoric, often followed by acts of violence.
So far, Mr. Trump has directed one operation to bolster his claim that he is perfectly willing to use force in an unpredictable manner: his decision a month ago to conduct an intensive, brief attack on a Syrian air base where American intelligence agencies say the Syrian government launched a chemical weapons attack on its own people. It had no follow-up.
But for North Korea, lashing out to send a message is an art form, practiced since the days when Mr. Kim’s grandfather ordered the seizure of an American ship, the Pueblo, in 1968, followed by the shooting down of an American reconnaissance plane, killing 31. Then, seven years ago, came the sinking of a South Korean naval vessel — most likely by a North Korean torpedo, though the country denies it — that took 46 lives.
The young Mr. Kim, who took over the following year after his father’s death, has worked to burnish his own madman credentials. He is believed to have ordered the cyberattack on Sony Pictures Entertainment that wiped out the company’s computer systems in 2014 and the killing of his half brother in Malaysia this year, part of a sustained campaign to eliminate potential rivals. More than a few have been executed with antiaircraft guns, just to make a point.
The fear is that small acts and mutual threats of war can lead to miscalculation. Only hours before Mr. Trump spoke, the North released a propaganda video showing the White House shattering apart in what looked like a nuclear blast. No one takes those videos seriously, but they indicate a state of mind in which every action has to have a reaction.
“That’s what I worry about the most,” Senator Edward J. Markey, Democrat of Massachusetts, said recently. “Rapid escalation.”
Past presidents have recognized the risk. It is notable that the shooting down of the American spy plane in Nixon’s time, one of the largest losses of Americans in a Cold War military attack, did not result in retaliation, in part for fear of rekindling the Korean War.
Behind the scenes in the Trump White House, officials are just beginning to debate how to react to potential North Korean acts. One of the most active debates is over what to do if the North attempts a test of an intercontinental ballistic missile. Should it be destroyed on the launchpad? Should the United States try to intercept it in midflight, with all the risks of escalation if that succeeds, and the risks of embarrassment if it fails?
Such questions are still being debated, as recently as during a meeting at the White House on Thursday, just as Mr. Trump and Mr. Tillerson were sending what sounded like uncoordinated messages.