By Song Sang-ho
SEOUL, July 16 (Yonhap) -- Amid rivalries with an assertive China and resurgent Russia, and tensions with Iran, the United States faces yet another complex foreign policy challenge from within its own alliance network: a rancorous diplomatic spat between South Korea and Japan.
Following Tokyo's recent export control measure, the relationship between the two American allies has been spiraling downward, fueling worries that their spat could hamper Washington's alliance-based drive to keep its geopolitical leadership and promote regional stability.
On July 4, Tokyo enforced tighter restrictions on exports to South Korea of three key industrial materials used in semiconductors and displays -- a move seen as a politically driven retaliatory step linked to last year's Supreme Court rulings here over Japan's wartime forced labor.
Seoul has been calling for Washington's mediation, while President Moon Jae-in appears set to confront Japan's economic jab head-on based on the claim that Tokyo's measure runs counter to free trade principles and could affect the global economy.
David Stilwell, the new top U.S. diplomat for East Asia policy, was set to arrive here Tuesday after his trip to Japan. His planned visit to Seoul renewed attention to whether Washington would step into the fray, though he has told Japanese media that Washington had no plan to mediate.
U.S. President Donald Trump's diplomacy prioritizing American interests has raised the prospect of Washington staying ambivalent over the Seoul-Tokyo tussle or demanding the two sides settle their issue bilaterally.
Adding to the prospect is lingering speculation that Washington could lean gradually toward an isolationist approach and scale back its overseas engagement to claw back lost power from erstwhile overseas engagement and military deployments.
But some analysts predicted that the growing geopolitical need to cement its alliance network could galvanize U.S. mediation.
"Despite Trump's America-first mantra, the mainstream view in the Pentagon and the State Department is that trilateral cooperation among South Korea, the U.S. and Japan is of great strategic importance," said Nam Chang-hee, a professor of international politics at Inha University.
"But the concern is that Trump already has his hands full given domestic politics and tensions with China and by extension in the Middle East. He doesn't seem to have sufficient room to tend to the squabble between Seoul and Tokyo," he added.
Indeed, the recurrent tensions between Seoul and Tokyo stemming from Japan's 1910-45 colonization of the peninsula have been a distraction for the U.S. engaging in a trade conflict with China, a chill with Russia over Washington's move to quit a Cold War-era arms control accord and friction over Iran's uranium enrichment activity.
What's more worrisome is the possibility that cracks could reopen in the U.S. alliance network, a centerpiece of Washington's Indo-Pacific strategy to promote what it calls the rules-based order that it thinks China is bent on altering.
In a Pentagon report published last month, the U.S. made it clear that South Korea and Japan are among the key partners in the strategy to counter potential challenges from China, Russia and North Korea that it portrayed as a "revisionist power, revitalized malign actor and rogue state," respectively.
A senior official at Seoul's foreign ministry said Monday that U.S. officials have pledged to see if there is any "suitable" role for Washington to play to defuse the Seoul-Tokyo spat while cautioning against the economic issue escalating into the security domain and hurting trilateral cooperation for regional stability.
It remains uncertain how deeply the U.S. would engage on the matter, as Trump's diplomacy appears to have been driven largely by his desire to reduce trade imbalances with allies and what he calls the unfair sharing of defense costs -- rather than by the strategic calculus of the alliances' value for America's longer-term regional leadership, analysts noted.
When tensions spiked between Seoul and Tokyo over the issue of Japan's wartime sexual slavery of South Korean women, Trump's predecessor, Barack Obama, played an active mediation role in line with his policy initiative, called a rebalance toward the Asia-Pacific.
Against the backdrop of China's growing assertiveness and the winding down of a drawn-out war in the Middle East, the Obama administration regarded South Korea and Japan as a centerpiece of its drive to keep American's preeminence in the strategically vital region.
During his visit to Seoul in 2014, Obama called the wartime sexual enslavement a "terrible, egregious violation of human rights" -- remarks that many saw as an implicit yet powerful call for Japan to seek a diplomatic solution to the humanitarian issue.
Such diplomatic pressure led to a 2015 agreement between Seoul and Tokyo to settle the thorny issue, under which Japan for the first time recognized its military's involvement that "has left deep scars on the honor and dignity" of former sex slaves.
Despite uncertainties over the U.S. role to reduce tensions between Seoul and Tokyo, Washington appears well aware of the need to promote cohesion in its alliance network.
In its diplomatic parlance highlighting its priority to strengthen its alliance system, Washington has called the U.S.-Japan alliance the cornerstone of peace and prosperity in the Indo-Pacific, and the South Korea-U.S. alliance the linchpin of peace and prosperity in Northeast Asia.
Some observers have raised questions over whether Washington could steer a middle course between Seoul and Tokyo when Japan appears to have been clearly attuned to the U.S. drive to counter China's assertiveness, while Seoul remains reluctant to make any explicit geopolitical decision.
A senior diplomat at Seoul's foreign ministry has quoted U.S. officials as saying it would be difficult to take any side between South Korea and Japan in the escalating trade row in a show of a delicate foreign policy challenge to Washington.
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