The aftermath of South Korea’s termination of a military information-sharing deal with Japan is worrying.

Serious damage to the US-led security cooperation with South Korea and Japan, not to mention Seoul-Tokyo relations, is inevitable.

Ending the General Security of Military Information Agreement is as good as pouring cold water on the already-strained ties between South Korea and Japan. One cannot but ask if the Moon Jae-in administration is determined to treat Japan as an enemy forever.

One of the most concerning problems is the South Korea-US alliance. On multiple occasions, Washington has expressed hopes for the renewal of the deal. But Cheong Wa Dae made a choice that ignored the ally’s hopes. North Korea and its ally, China, are undoubtedly happy at the decision to end the deal.

Cheong Wa Dae said it considered “national interests,” but that explanation failed to ease concerns about South Korea being diplomatically alienated and a security vacuum arising.

A Cheong Wa Dae official said the US “understands” its decision to exit the GSOMIA, but the Pentagon issued a statement expressing its “strong concern and disappointment.” US Secretary of State Mike Pompeo told a press conference that “we are disappointed.”

Cacophony is worrisome. Cheong Wa Dae should explain its differences with the US.

The word, “disappointed,” is seldom used in diplomatic circles. It is uncommon for Washington to criticize its ally with the expression of “disappointed.” The rhetoric implies there is a profound impact on US interests.

Cheong Wa Dae shunned disputing the US comments directly. It rather touted the exit from the deal as an occasion to upgrade the US alliance. That is sophistry apparently to veil the crumbling alliance. One will hardly be on better terms with someone who says he is disappointed. Cheong Wa Dae is keen on public opinion of the current government. The ruling camp seems to believe that it can rally support for Moon with anti-Japanese measures including the termination of the deal.

It is unusual for the US to refer to the South Korean government as the Moon (Jae-in) administration in its official comment. This expression highlights the exit of the deal as Moon’s decision. It alludes that his government is veering off the track of traditional alliance.

For the US, the GSOMIA is an axis of its tripartite security system with South Korea and Japan. Pushed by strong US persuasion, South Korea and Japan entered into the accord in 2016. It was regarded as a cornerstone of the three-nation security cooperation.

Korea experts in the US reportedly view the scrapping of the agreement as a move to break away from the trilateral security system. If cooperation with allies wobbles while the North is not denuclearized at all, the South will likely be less heard on the international stage. The diplomatic isolation of the South will only strengthen the North’s strategy regarding negotiations to denuclearize and inter-Korean relations.

North Korea test-fired two “super-large rockets” on Saturday, two days after the announcement of the decision to scrap the GSOMIA. It was the fifth launch of projectiles this month. The North appears to be launching missiles and rockets without reservation. It will attempt to test the South’s ability to detect its missile launches after the termination of the deal. Given the North’s escalating provocations, information sharing among allies is all the more necessary now.

South Korea has no security interests to gain from ending the deal. US mediation in trade spats between Seoul and Tokyo is effectively off the table. South Korea’s cost of keeping the US alliance may rise and Japan will likely take countermeasures.

Nonetheless, Cheong Wa Dae’s explanation is insufficient and unconvincing. So it faces suspicions that it chose to fight Japan and foster anti-Japanese sentiment for political gains, or that it sought to distract the people from the high-profile corruption allegations facing Cho Kuk, nominated by Moon as justice minister.

What are the national interests that Cheong Wa Dae seeks?

It ought to tell the people where it is leading the nation in light of the security issues. It should reflect its big picture of alliances and diplomacy. The important thing is that the US alliance must not be sacrificed for political or ideological reasons. It undermines national interests and imperils the nation.