Such an operation would be highly risky even if it would be far more surgical than Mr. Trump’s threat this week to “totally destroy North Korea” if forced to defend the United States or its allies. Should the United States find that North Korea was loading a nuclear warhead onto an intercontinental ballistic missile, the choices would be limited, according to officials who have participated over the years in the Pentagon’s secret war games designed to anticipate various forms of a crisis on the Korean Peninsula.

For the moment, despite his bellicose language, Mr. Trump has chosen the path of economic pressure, signing a new order on Thursday intended to cut North Korea off from the international banking system with measures that, in some ways, went significantly beyond previous efforts to punish outlier nations like Iran. The White House hopes that further isolating North Korea will eventually force Mr. Kim to come to the negotiating table.

Conservatives who bristled at what they considered Mr. Obama’s weak approach offered few complaints about the president’s taunting escalation, arguing that Mr. Kim was a bully and the best way to stand up to a bully was to match him, rhetorical blow for rhetorical blow. Some urged Mr. Trump to even go beyond that, given that North Korea now has a significant nuclear arsenal with missiles that could even strike the United States.

“The question is, do you wait for one of those? Or, two?” Representative Duncan Hunter, a California Republican, said in a radio interview Thursday. “Do you preemptively strike them? And that’s what the president has to wrestle with. I would preemptively strike them. You could call it declaring war, call it whatever you want.”

John Hannah, who served as national security adviser to former Vice President Dick Cheney, said it was hard to imagine any previous president “getting into the rhetorical muck with the likes of” Mr. Kim. But he noted that all of those predecessors “failed miserably to resolve the North Korean nuclear threat,” their measured tones doing nothing to stop a dictator from developing a devastating arsenal.

“Is it a high risk strategy?” Mr. Hannah, now senior counselor at the Foundation for Defense of Democracies, said of Mr. Trump’s approach. “For sure. Is it worth trying, in light of the historical record of dismal U.S. failure to stop the North Korean program? Perhaps.”