TOKYO — Every time North Korea does something provocative — which is often — Washington insists that Pyongyang must give up its nuclear weapons program.
Just last weekend, days after North Korea launched its most high-tech intercontinental ballistic missile yet, national security adviser H.R. McMaster said that President Trump "is committed to the total denuclearization of the Korean Peninsula."
Not that this line is confined to the Trump administration. The Obama and Bush administrations before it also repeatedly insisted that North Korea must denuclearize.
That might have been a realistic aim before Pyongyang could build a hydrogen bomb and missiles that can reach the United States. It's just a matter of time before the North Koreans can put the two together — if they can't already.
The Trump administration won't admit it, but North Korea is now a nuclear weapons power, analysts say. Why would Kim Jong Un's cash-strapped regime spend so much time and money on building these weapons only to give them up? And even if they were prepared to bargain them away eventually, why would they do so now, when Trump and his top aides are threatening military action?
"We've seen no indication in recent years that they are interested in denuclearization," said Mira Rapp-Hooper, a North Korea expert at Yale Law School who was an Asia adviser to Hillary Clinton's presidential campaign. "So it's difficult to rationalize how we are still so fixated on it."
Vipin Narang, a nuclear nonproliferation specialist at MIT, agreed.
"It's a fantasy that they're going to willingly give up their nuclear programs so long as Kim is in power. He saw the fate of Saddam and Gaddafi — why would he give up his nuclear weapons?" asked Narang, referring to the former leaders of Iraq and Libya, both of whom are now deposed and dead.
Trump's willingness to pull out of the international nuclear deal with Iran would only heighten North Korea's mistrust of a negotiated denuclearization agreement with the United States, he said.
For three generations, since the current leader's grandfather, Kim Il Sung, was in power, North Korea has pursued nuclear weapons as a way to deter the United States and ensure the regime's survival.
Pyongyang's perceived need for a powerful deterrent has only increased since Kim Jong Un took power six years ago this month. Young and inexperienced — he was 27 when he succeeded his father and had no military background — the third Kim has aggressively pursued nuclear weapons as a way to fend off outside threats and bolster his legitimacy inside North Korea.
"The only way you can convince them to denuclearize is to make nuclear armament costly enough to destabilize the regime," said Chun Yung-woo, a former South Korean nuclear negotiator with the North. "To do that would require a total economic blockade to suffocate the regime."
Since coming to power, Kim has ordered four nuclear tests, including the September detonation of what his regime claimed — and outside experts generally agree — was a hydrogen bomb. At the same time, he has presided over astonishing improvements in North Korea's ballistic missile program, culminating last month with the launch of a missile that puts all of the United States technically within his reach.
His regime has made these advances despite increasingly tight international sanctions aimed at cutting off its access to funding and parts, and despite increasingly vehement warnings from its traditional patron, China.
In both public and private meetings in Europe this year, North Korean representatives have repeatedly insisted on being accepted as a nuclear-armed state.
Choe Son Hui, the director of U.S. affairs in North Korea's Foreign Ministry, said recently that Washington will have "have to put up" with the fact that her country now has nuclear weapons. "This is a matter of life and death for us," she said at an October nonproliferation conference in Moscow.
Acknowledging that North Korea has nuclear weapons is a step that the Trump administration — like Obama's before it — has been unwilling to take. "We don't want to admit that our policy has failed for successive presidents," Narang said.
Both administrations have urged China to use its leverage over North Korea. While Beijing says that denuclearization is its fundamental objective, it takes a much longer view of the process.
"From Beijing's perspective, it is unrealistic to expect an immediate denuclearization of North Korea — especially since the world has so far proved unable to even prevent the North's present capabilities from growing," Tong Zhao, a fellow at the Carnegie-Tsinghua Center for Global Policy, wrote before Trump's visit to Beijing last month.
In Washington, however, there is a growing sense that time is not on the United States' side.
CIA Director Mike Pompeo said in October that North Korea was only a matter of months away from perfecting its nuclear weapons program.
"They are close enough now in their capabilities that from a U.S. policy perspective, we ought to behave as if we are on the cusp of them achieving that objective," he said at the Foundation for Defense of Democracies, a conservative think tank.
"There are ways to address this problem short of armed conflict," McMaster, the national security adviser, said Saturday, "but it is a race because he's getting closer and closer, and there's not much time left."
Trump and McMaster have repeatedly said that military options are on the table, a message that North Korea takes especially seriously when U.S. fighter jets are practicing precision strikes on the Korean Peninsula.
This is coupled with frequent assertions that Kim is an irrational madman — a "sick puppy," as Trump most recently put it — who can't be deterred in the way that the U.S. military deterred his father and grandfather.
"There are a lot of people who argue that there's still a window to stop North Korea from getting an ICBM with a nuclear warhead to use against the United States," said Narang, referring to an intercontinental ballistic missile. "They're telling themselves that if they strike now, worst-case scenario: Only Japan and South Korea will eat a nuclear weapon."