Last month on The Diplomat, Van Jackson made an important argument about South Korea's increasingly notable silence on freedom of navigation in the South China Sea.

Jackson, like many analysts, recognizes growing Chinese misbehavior there, most obviously the destabilizing island-reclamation strategy and expansive sovereignty claims it fuels. Jackson would like to see greater South Korean engagement (actually, any at all). He rightfully notes that the more unified the Asian front regarding rules in the Western Pacific, the more likely China is to moderate its actions. 

Where is the ROK on the South China Sea?

South Korea is a U.S. ally. As a trading state heavily dependent on open, safe sea-lanes, it has a strong interest in freedom of navigation rules. As a proximate neighbor of China, it has a similarly strong interest in China's socialization into a rules-bound regional community. Countries around China's periphery, from Japan to India, worry that if China is not rebuffed in the East and South China Seas, a sense of hegemonic dominance in the region may grow in Beijing. These minor conflicts are widely seen as the leading edge of the larger question of China's regional intentions as it grows ever stronger.

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These concerns about China's integration or rejection of regional rules are, of course, well known. But Jackson helpfully fingers the growing unease in the U.S. over South Korea's hedging on China. Besides silence on the South China Sea question—on which almost every other regional state has weighed in against China—the South Koreans also quickly signed up for the Chinese-led Asian Infrastructure Investment Bank, and they have dragged their feet for years on missile defense deployment.

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The corresponding American anxiety is predictable. In Washington, it seems obvious that South Korea should sign up with the U.S. camp regarding China. The Republic of Korea (ROK) is a U.S. ally, which spends far less on defense than it otherwise would because of the US defense commitment. Why should the U.S. provide world-class defense to the ROK without something in return?

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Separating China from North Korea is vastly more valuable

The ROK's silence on China in the region, and the trust or at least credibility which that brings in Beijing, has a huge benefit not mentioned in Jackson's essay and elsewhere in this debate: gradually convincing China that it can safely give up it's North Korean 'buffer.' The current Chinese-North Korean relationship is the coldest it has ever been in the post-Cold War period due to vigorous diplomacy by the Park Geun-Hye Administration and its necessary (if unfortunate) reticence on Chinese regional behavior. This Sino-North Korean drift is a fantastic turn of events, which should not be jeopardized with minor South Korean gestures regarding the South China Sea.

North Korea is not even close to being economically self-sufficient (ironic, given its autarkic ideology). Specifically, North Korea has great trouble feeding its population on its own; the last time it had to, it suffered a famine that killed roughly 10% of its population. Nor can it power its machinery, vehicles, power-grids and so on without fuel imports. Nor can its decadent elites enjoy the fruits of tyranny—mansions, cars, top-shelf liquor, yachts and the rest—without a pipeline to the world and access to banks and credit. Permanent subsidization is required.

During the Cold War, the USSR and China were maneuvered into competing for a North Korean 'tilt' by sponsoring its inefficient economy. After the Cold War, the U.S., South Korea and Japan also occasionally subsidized the DRPK as part of various deals (which would invariably collapse). North Korea also routinely asks the UN and any other country that will listen for aid of almost any sort.

But this decades-old 'aid hunt' is slowly exhausting itself. Last year's definitive UN report on North Korea's ghastly human rights record makes it harder for UN agencies to assist Pyongyang without crushing criticism in the democratic world. The regionally relevant democracies—Japan, the U.S. and South Korea—have also been suckered once too often by the North to help again without serious concessions. The South Korean Sunshine Policy has been defeated twice at the polls, and the current U.S. attitude of 'strategic patience' means in practice no aid without verifiable denuclearization, which will not happen. The USSR is gone, and Russia today is too weak, economically stagnant and underpowered in Asia to play the supporting role it once did. Other rogues like Iran or Venezuela may sympathies with the North's aggressive anti-Americanism but can hardly muster the aid flows needed.

That leaves China.

China is the last lifeline. It provides the fuel that keeps the lights on and the cars on the road. It looks the other way on sanctions-busting luxury imports. Robust cross-border networks help meet basic needs for food, clothing and consumer goods for the general population. China provides a location for North Korean financial activities, which are often illicit. Beijing gives diplomatic cover in international organizations, including blocking a referral of Pyongyang to the International Criminal Court. In the language of game theory, China is the final hunter in the 'stag hunt' game needed to pin down the North.

To cut this lifeline would almost certainly produce a regime crisis. The population would once again be thrown into the penury of the famine years, while at the top, the cash, lifestyle and goodies for elites would dry up. Given that the Kim family has essentially bought off the army brass for decades to prevent a coup, the prospect of Pyongyang elites turning on each other over a diminishing budgetary and resource pie is arguably the greatest threat to Kimist rule. The Kim family almost certainly senses this vulnerability.

Prioritizing North Korean collapse

The end of Chinese support is a necessary (if not sufficient) cause for North Korea's eventual collapse. South Korean President Park's robust efforts to woo Beijing have helped push China and North Korea apart in the last few years. This is a huge achievement—arguably the most important in her otherwise scandal-laden presidency. For South Korea to weigh in on the South China Sea would jeopardies this tenuous breakthrough. Beijing must believe South Korea is at least neutral regarding Chinese power before it will give up Pyongyang. Given that U.S. forces are stationed in South Korea, Park must be flattering Xi Jingping quite a lot, and she has probably bit her tongue on other issues, like the South China Sea. But ultimately who cares? Cutting Pyongyang off from its last sponsor would be a sea-change and is well worth these costs.

Ideally, South Korea, as a fellow regional democracy and U.S. ally with strong freedom of navigation interests, would support the regional pushback on China in the South China Sea. But the realities of Chinese growth force tough choices. As I have argued before, rigid democratic maximalism regarding China will openly provoke it; Asia does not need ideological neocons. The democracies need to find ways to work with the realities of Chinese power without betraying core values. Abandoning Taiwan, for example, is a bridge too far in such accommodation. But in the South China Sea (and AIIB), a bit of South Korean silence or free-riding is a tolerable swap for a much greater gain.

The U.S. has many other allies and friends on the South China Sea issue. Laying the groundwork for the cessation of Chinese support for Pyongyang is of far greater strategic significance to the U.S., and just about everyone else, than the mild extra weight South Korea could bring on the South China Sea.

This piece first appeared in the Lowy Interpreter here. 

Image: Creative Commons 2.0.