TOKYO -- South Korea's decision to scrap an intelligence-sharing pact with Japan has laid bare the extent of Seoul's split with Tokyo and Washington on security strategy, dropping a gift in the laps of North Korea, China and Russia.
The U.S. Defense Department was quick to express "strong concern and disappointment" Thursday over Seoul's withdrawal from the General Security of Military Information Agreement with Japan. America rarely takes such a critical tone with allies.
Washington is worried less about the direct impact on its military operations than about the risk that South Korea will continue to tilt away from the U.S.-Japan camp and toward China and North Korea.
Such a shift could embolden those two countries and Russia to act more aggressively in the region. And over the long term, an American government source said, there is a danger of the Korean Peninsula becoming steeped in Chinese influence.
Seoul's stated reason for moving to terminate the agreement in rejection of U.S. calls for restraint was the Japanese government's imposition of curbs on exports to South Korea. But even if this was the direct trigger, a more significant factor is that the administration of President Moon Jae-in is not entirely convinced that the pact was necessary.
Both Tokyo and Washington had repeatedly urged Seoul to stay in the deal, insisting that cooperation among the three countries was essential to respond promptly to North Korean provocations and to handle China's rapid military buildup. The Russian military has also grown more active in Asia in recent years -- as shown by a recent run-in over the Sea of Japan.
But the Moon administration appears not to share its partners' growing sense of urgency, and likely is less concerned about maintaining a united front.
And little wonder. Moon has embraced reconciliation with, rather than pressure on, North Korea as a means to ease tensions on the peninsula. Some in Seoul even reportedly argue that it would be better to avoid overemphasizing unity with Japan and the U.S., which could pose an obstacle to rapprochement.
Even U.S. President Donald Trump, who is himself keen on talks with the North, has expressed frustration with Moon's conciliatory stance, diplomatic sources say.
A split is evident with regard to China as well. Beijing's expansion of military power in the East and South China seas has caused alarm in Washington and Tokyo, and the allies have partnered with Australia and India in a bid to counter it. The Indo-Pacific Strategy being promoted by the U.S. is part of this effort.
But in Seoul, "there's still some reluctance to get too deeply involved in the Indo-Pacific Strategy because of the backlash it could invite from China," a South Korean diplomatic adviser said.
South Korea has been burned by such moves before. When Seoul in 2016 approved the U.S. military's move deployment of a missile defense on South Korean soil, Beijing was infuriated. South Korea bore the brunt of this anger with Chinese moves that amounted to economic retaliation.
South Korea's growing economic reliance on China is another consideration. The share of South Korean exports that went to China came to about 27% last year -- far more than the 17% to Japan and the U.S. combined. The importance of this trade makes it difficult for Seoul to take a tough stance on security matters with Beijing.
These widening divides in diplomatic strategy led to the demise of the intelligence-sharing agreement. Even if the deal is revived, it is unlikely to fully serve its purpose as long as the rift persists. Should South Korea continue to pursue a different diplomatic direction from Japan and the U.S., it will be harder for both sides to find opportunities to share what they know and what they are planning.
To repair the relationship, the partners will need to more closely align their views on China, North Korea and Russia. Failure would risk allowing Pyongyang to accelerate its nuclear weapons development and Beijing and Moscow to further undermine Japan and the U.S. diplomatically and militarily.