US-South Korea-Japan security cooperation has long been a study in frustration. A primary obstacle has been Seoul’s reluctance to work with its partners, primarily because of historical grievances – and the resulting political sensitivities – that dominate relations with Japan. Another important element has been diverging views between Seoul on one hand and Washington and Tokyo on the other regarding China and the degree to which Beijing constitutes a security threat.  That may be changing: some ROK strategists are reassessing China’s role in South Korean security, and taking a harder look at Beijing’s intentions. It is still early, but this shift offers opportunities to Tokyo and Washington.

There is a well-rehearsed – and easily understood – list of reasons why Seoul has traditionally had a more benign view of China. China is a geographic reality that will always loom large over the ROK; it cannot withdraw from the region. Following its explosive growth, China has become “the center of economic gravity” for the ROK, prompting concerns about Korea’s economic dependence on its giant neighbor.

In the Park Geun-hye administration, there was a belief – nurtured by China – that the road to North Korea ran through Beijing. That encouraged a tactical accommodation with China that looked – wrongly – to some as though Seoul was shedding the US political and security alliance. That concern resurfaced when progressive Moon Jae-in moved into the Blue House. Whatever the reality, Chinese influence was magnified by the deeply-rooted belief that South Korea is a small power, subject to the mercies of larger neighbors and allies. As a result, in strategic discussions like those conducted by Pacific Forum, ROK interlocutors bluntly and frequently state that trilateral security cooperation against China is a nonstarter. The Seoul government cannot – or will not – pursue cooperation with the US and Japan if it risks an adversarial position against China.

That thinking is evolving. The first trigger was Beijing’s heavy-handed response to the ROK decision to deploy Terminal High Altitude Area Defense (THAAD) missile defense systems against the North Korean threat. China asserts that THAAD threatens its own deterrent and demands that Seoul reverse its decision and dismantle the batteries. South Korea’s refusal to honor those demands – the real source of Chinese pique, not a specious claim about undermining its deterrent – has prompted sanctions and other forms of economic retaliation that have imposed significant costs on ROK businesses and angered the public. In discussions in Seoul, some ROK officials complained about Beijing’s failure to honor recent promises to move beyond this dispute and restore economic relations to normal.

A second grievance is the growing number of Chinese military aircraft that entered South Korean airspace this year. This has inflamed the irritant created by China’s surprise 2013 announcement of a Chinese Air Defense Identification Zone (CHADIZ), one that overlaps Korea’s own ADIZ. This growing presence – and the appearance of Chinese military aircraft off the east coast of the Korean Peninsula – prompted criticism by ROK officials. This is another reminder of China’s overbearing presence on the Peninsula – a function of its inescapable geographic proximity.

Official irritation is matched by growing anger among the public. The ROK public’s view of China is steadily declining. According to Asan Institute polling, views of China reached an all-time low in March 2017 and there is a growing tendency to see the US as the country’s most important economic partner, surpassing even China. A renewed inclination among Koreans to see the US, rather than China, as central to their economic future would undercut a key source of Chinese influence in the ROK.

This new thinking is taking shape as the events of 2018, the flurry of summits in particular, push strategists to reassess regional dynamics and question key assumptions in their planning. There is a readiness to incorporate this hardening of views toward Beijing into policy recommendations. As one security official explained, the ROK is looking a decade ahead and a strategy that does not take into account China and Russia is of no use.

In one conversation, the South China Sea was likened to China’s soft belly and the Korean Peninsula as its neck. In a striking reversal of a well-known metaphor, South Korea could be, it was asserted, “a dagger” against China – if Seoul develops the capabilities to threaten Chinese assets at land or at sea. (Cynics will note that such options are always available. True, but conversations in Seoul suggested that those options are being actively explored today. One interlocutor added that just because these ideas aren’t in circulation doesn’t mean they aren’t being discussed.)

If these new ideas are taking root, then US and Japanese officials need to be careful in response to them to realize the potential of trilateral cooperation. One good way to begin is sharing strategic assessments of Northeast Asian regional dynamics one decade from now. What are the likely relationships among key players? What are shared concerns and warning signs? What can be done to dampen tension and build in stability? What are the most likely contingencies and how can Washington, Seoul, and Tokyo prepare for them?

Ultimately, however, the fate of trilateral cooperation depends on a more fundamental question: can – and should – the US-ROK alliance survive for another decade? If the answer is yes – and this should be proven, not assumed – then the two governments must figure out how to ensure that future. The answer will be more complex than ever given fast-moving realities of Northeast Asia. Critical will be the ability of the two governments to create interdependencies and a sense of shared interest in a drastically different strategic environment. Once the US-ROK alliance is assured, then those two governments can work with Japan.

Caution is in order, however. The ROK isn’t looking for conflict with China and South Korea will continue to use ambiguity to avoid friction with Beijing. While Koreans prefer a rules-based system based on established norms and values, they quickly add that “they are not ready to join a great power competition between China and the US.” Taking sides “is too much to ask.”

Perhaps that remains true for now, but US strategists and their partners in Asia should be alert to this shift in Korean thinking, examining ways to nurture changes that facilitate cooperation and working to minimize issues that could slow or stop this evolution.

Brad Glosserman ([email protected]) is a senior adviser at Pacific Forum and a visiting professor at the Tama University Center for Rule Making Strategies.

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