American officials deployed unusually harsh language toward South Korea’s Moon Jae-in administration after Seoul on Thursday announced that it was terminating GSOMIA, a US-sponsored intelligence-sharing pact with Japan.

As relations between Seoul and Tokyo, the two key US allies in Northeast Asia, continued to plummet, some warned darkly that the unilateral cancellation of the agreement could be the start of an irreversible fracture in US-led security efforts in the region. And indeed, in a televised briefing, a senior South Korean official made clear Seoul was prioritizing national interest and bilateral relations over multilateralism.

In comments picked up by South Korean media Friday, US Secretary of State Mike Pompeo said he was “disappointed” by the decision, while the State Department said Seoul’s move “reflects a serious misapprehension on the part of the Moon Administration regarding the serious security challenges we face in Northeast Asia.”

The US Department of Defense also spoke up, expressing “strong concern and disappointment that the Moon Administration has withheld its renewal” of the agreement.

Annual renewal of the GSOMIA, or General Security of Military Intelligence Agreement, had been set for Saturday. Given the three-month time window required for termination, the agreement, inaugurated in 2016 under US auspices, will expire in November.

Subsequently, US Secretary of Defense Mark Esper expressed his “concerns” during a telephone conversation with his South Korean counterpart.

Critically for Washington’s interests in the highly strategic region, GSOMIA represented the only official alliance tie between the militaries of the two Northeast Asian democracies and US allies. The two countries are frequently at loggerheads over territorial and historical issues, but relations are in virtual crisis at present as they indulge in a trade war that has, as of yesterday, spilled over into the security sphere.

The blunt, public language Washington aimed at Seoul is telling, given its preferred restraint in prior situations.

The United States has long been keen to create a trilateral united front in a region where it faces off against China, North Korea and Russia. As such, it customarily treats Japan and South Korea with kid gloves, not wishing to be seen to favor one capital over the other in their endless disputes that originated in Japan’s 1910-1945 colonial rule over the peninsula.

‘Strategic stupidity’

If official US comments were condemnatory, they were at least politely phrased. US pundits were far more forthright.

Experts quoted by The Nelson Report, a daily, Asia-focused geopolitical newsletter that quotes from and is believed to reach an influential readership in Washington, DC, and elsewhere, removed their gloves in a scathing series of outbursts.

“There is no question regarding the strategic stupidity of this decision,” stated one.

Another US expert, who has held high-level diplomatic positions in South Korea in the past, said his original reaction to the news was “unprintable.”

He went on to say: “This is a foolish and misguided decision that historians years from now may well look back upon and say that it signaled the beginning of the end of the US-centric security architecture in Northeast Asia. What a strategic miscalculation!”

South Korean President Moon is a “fool,” added yet another expert, who formerly held prominent positions in US intelligence.

Referring to the popular sentiment from which the Moon administration says it takes its lead, and the widespread distrust of Japan within South Korea, the expert added, “Where does he think [South Korean] security threats come from? This is ‘Korea First’ tribalism, the wisdom of the crowd.”

Possibly stung by the barrage of criticism, Seoul returned fire in the afternoon via a televised briefing delivered by South Korea’s Deputy National Security Adviser Kim Hyun-chong.

‘National interest’

Some experts have said that, given Japan’s superior intelligence-collection assets, South Korea’s killing of the agreement would damage it more than Japan. Kim, however, insisted that the termination of GSOMIA was was no knee-jerk decision, but “a product of extensive deliberations and taken in accordance with national interest.”

After accusing Japan of declining to respond to repeated Korean outreach in their ongoing trade dispute, and of declining to acknowledge an August 15 Liberation Day speech in which Moon had sounded a conciliatory note, Kim said Japan’s actions were “a clear affront to our national pride and a breach of diplomatic etiquette.”

With a range of senior US defense officials having visited the region in recent weeks, Kim said that Seoul had “maintained close communications with the United States in the course of reviewing the conflict with Japan as well as GSOMIA.”

However, he conceded, “It’s true that the U.S. hoped for the extension of the agreement.”

Kim added that Seoul would work to “actively upgrade” its bilateral alliance with the United States.

Noting that in the current global climate “multilateralism has regressed while there is a pervading sense of countries putting their interests first,” he said Seoul would increase its purchase of defense goods and increase its capabilities. This would “conform to the US desire of seeing an ally increase its contributions to security,” he said,

In addition to equipment purchases, there are possible avenues via which Seoul could repair its apparently damaged standing with the US defense establishment.

Bilateral cost-sharing negotiations on the basing of some 28,500 US troops in South Korea are expected to begin next month amid reports, rumors and indications from multiple sources that Washington will demand a higher price this year than in previous years.

A higher prize to be paid by Seoul – some anonymously-sourced Korean reports even claim it could be a staggering five times the previous year’s expenditure – would synch with US President Donald Trump’s oft-stated demand for allies to pay more for their defense.

There is also considerable speculation underway that South Korea could dispatch military assets to the Persian Gulf to cooperate with US forces in that troubled region. That would represents one advantage Seoul has over Tokyo – which faces significant constitutional restraints on overseas deployments.