In his first State of the Union speech, President Donald Trump devoted a large amount of time to discussing the situation with North Korea. He described the country much in the same way that George W. Bush had described Iraq in 2002: as a brutal, irrational regime whose weapons pose an intolerable threat to the American homeland.

But though it was worrisome to hear Trump make a thinly veiled case for another preventive war, that wasn’t the most troubling piece of news about North Korea policy to come out last night.

Just before Trump’s speech began, the Washington Post reported that Trump’s pick for ambassador to South Korea — Victor Cha, one of America’s most respected North Korea experts — was being withdrawn. The reason cited by the Post was a chilling one: Cha had opposed the administration’s proposal for a limited military strike in a private meeting. Cha all but confirmed this himself a few hours after the news broke when he published an op-ed in the same paper criticizing the idea of attacking North Korea.

Cha’s withdrawal seriously worried South Korea’s government, which had formally approved the pick. It also terrified North Korea experts, who saw it as a clear sign that the war talk wasn’t merely chatter.

“This [withdrawing Cha as a nominee] suggests that the administration is seriously considering ... a strike,” says Kingston Reif, director for disarmament and threat reduction policy at the Arms Control Association.

Steve Saideman, a scholar of US foreign policy at Carleton University, put it more bluntly on Twitter: “A new Korean war is now perhaps more likely than not in 2018.”

Why the Victor Cha episode makes it seem like war is coming

Cha is a leading North Korea expert. A longtime scholar-practitioner, he served in the George W. Bush administration from 2004 to 2007 as the National Security Council’s director for Asian affairs and is currently a professor at Georgetown University.

He’s also on the hawkish end of the North Korea expert spectrum. He’s endorsed taking aggressive steps to protect against the North’s nuclear program, like setting up a naval cordon around North Korea to intercept any nuclear material it tries to sell to terrorists or other rogue regimes.

A North Korea hawk who’s both deeply experienced and widely respected seems like a perfect pick for the Trump administration, so it’s telling that Cha’s nomination was apparently derailed because he was too dovish for the Trump team.

One detail of the incident, reported by the Financial Times, really hammers this point home:

According to the two people familiar with the discussions between Mr Cha and the White House, he was asked by officials whether he was prepared to help manage the evacuation of American citizens from South Korea — an operation known as non-combatant evacuation operations — that would almost certainly be implemented before any military strike. The two people said Mr Cha, who is seen as on the hawkish side of the spectrum on North Korea, had expressed his reservations about any kind of military strike.

This account sure makes it seem like the Trump administration is imminently preparing for an attack on North Korea — to the point that they’re seriously considering the logistics of how to protect the large number of American civilians in the South. Cha objected to the idea of an attack on North Korea, which seems to have disqualified him from consideration.

The fact that Cha published an op-ed afterward decrying war is also significant. He specifically criticized the logic behind a “bloody nose” strike — a limited attack on North Korean military and nuclear installations that aims not to escalate the situation to all-out war, but show Pyongyang that further attempts to advance its nuclear program will be met with force. Apparently, it’s the type of military action that the Trump team is leaning toward — and Cha thinks its too dangerous.

“If we believe that Kim [Jong Un] is undeterrable without such a strike, how can we also believe that a strike will deter him from responding in kind?” Cha wrote. “And if Kim is unpredictable, impulsive and bordering on irrational, how can we control the escalation ladder, which is premised on an adversary’s rational understanding of signals and deterrence?”

The fact that Cha was dismissed after airing this kind of criticism internally is, experts say, a clear sign that the administration is taking the notion of war very seriously.

“That Victor Cha felt compelled to go on the record is a sign of how frighteningly real the risk of strikes really is,” writes Mira Rapp-Hooper, a North Korea expert at Yale.

Even if war isn’t imminent, the Cha situation is troubling

It’s also possible that this threat of force is a bluff, and that Cha’s dismissal is part of the Trump administration’s posturing.

“The president is really trying to give the impression that war is possible in order to intimidate North Korea into behaving more cautiously,” says Jenny Town, assistant director of the US-Korea Institute at Johns Hopkins. “In such a strategy, you can’t have naysayers, especially in your own administration, if you want the threat to be credible.”

But if this is true, and many informed observers think it isn’t, then taking Cha out of consideration is still dangerous. The more signs the Trump administration sends that they’re serious about war, the more likely they are to start one unintentionally.

“The problem of such a strategy, of course, is that in the process of trying to establish a credible threat, North Korea might actually start to believe him — and instead of being intimidated, will up the ante more,” Town adds. “The question being, at what point do we accidentally stumble into an unnecessary and completely avoidable war?”

The lack of an ambassador to Seoul makes this scenario more likely. Ambassadors play critical roles both in reassuring allies and in conveying allied views back to Washington. It’s very rare to have no ambassador in place for a country that’s an important ally at this point in a new administration — for good reason.

“Given the tensions on the peninsula and the importance of the US-Korea alliance, it is worse than diplomatic malpractice that there remains no US ambassador in Seoul,” Reif, the Arms Control Association expert, says.

In the event of a crisis between the US and North Korea, Cha likely would have been an important voice for caution inside the administration. He also would have been able to efficiently convey vital information about the North from the South Korean government to the highest levels of the US government, as well as convey the South Korean government’s skepticism about any kind of military escalation.

Cha’s appointment, in short, would have provided a critical check on a crisis spinning out of control. There’s no chance of that now.

“To drop an ambassador nomination for a major treaty ally in the midst of a major crisis is unprecedented,” writes Abraham Denmark, who served as deputy assistant secretary for East Asia in the Obama administration. “The fact that it’s someone as knowledgeable and qualified as Victor Cha should give everyone pause.”