Last week I was invited by the Korean National Defense University to present at a conference on regional powers' responses to Korean unification. It is an important topic, because I think it is increasingly clear to South Koreans, or at least the Government, that unification will be more impacted by regional players, especially China, than they might like. That is to say that a German-style, wholesale absorption of North Korea with little regional input, beyond reluctant acquiescence, seems unlikely.

Korean DMZ, view from North Korea (Flickr/julia_e)

In 1990, the Soviet Union was collapsing. Mikhail Gorbachev was desperate to lower the Soviet military burden and cut the costs of the Eastern European albatross. (Where the Eastern European glacis had been a security boon in the 40s and 50s, by the 70s it had become a serious economic weight, as had many of the USSR's allies, who nearly all demanded subsidies, North Korea included.) In this environment, Gorbachev effectively 'sold' the German Democratic Republic for around 75 billion marks, plus a much-disputed reassurance from US Secretary of State Jim Baker that NATO would not expand east.

China, North Korea's patron today, faces no such constraints. China is rising, not collapsing. It does not need the money; its ability to support a stumbling client is improving, not declining. Hence I have argued repeatedly that Korean unification will face a harder course than Germany's. And this is exacerbated because North Korea is in much worse condition than East Germany was, and South Korea is less capable of absorbing North Korea in one shot than West Germany was. Also, the US is not nearly as regionally dominant in East Asia today as it was in Europe in 1990.

With that in mind, I argued that China does in fact have a pretty profound security interest in keeping North Korea afloat, and hence delaying unification as long as possible. As is often the case with Chinese foreign policy toward North Korea, I find this cynical and manipulative. China manipulates arguably the worst country on earth with little care for the horrible oppression going on within, and it asserts the importance of its own 're-unification' (with Taiwan) while tacitly acting to deny that to the Koreans.

Beijing should not be surprised at the dearth of strategic trust it faces. It has earned it. But from a strictly realpolitik perspective, North Korea serves at least three basic purposes to Beijing:

1. North Korea, as Chinese analysts openly admit, is a 'buffer' between China and the robust democracies of South Korea, Japan, and the US. International relations work on buffer states has noted that they often facilitate great power peace by reducing the perception of zero-sum territorial competition. Today's conflict in Ukraine may be seen as Russia's attempt to keep a buffer between it and NATO. Similarly, China perceives the value in North Korea 'distancing' the democratic practices and military power of the Republic of Korea (ROK), Japan, and the US from its border. The US and its Asian allies are not just a potential military threat to Chinese territory, most obviously in the case of a Sino-US conflict. They also represent, as democracies, a regime challenge to China's post-communist oligarchy. The persistence of North Korea keeps alive the useful fiction for China that somewhat 'communist' states continue to exist, and that democracy is not an ever-widening global norm, at least not in Asia.

2. Korea's division distracts US attention from the biggest foreign policy issue for China – the future of Taiwan. In its long-standing effort to end Taiwanese 'splittism', China's first goal is to inhibit US intervention, diplomatic or otherwise. As long as North Korean shenanigans keep Washington focused on northeast Asia, strategic attention and military resources are not available for Taiwan contingencies. This likely explains Beijing's frustratingly tepid response to even egregious North Korean behavior such as the 2010 sinking of the ROKS Cheonan or the shelling of Yeonpyeong Island. So long as North Korean bad behavior does not become too dangerous, it serves a running Chinese interest in distracting the US.

3. Korea's division helps inhibit a Korean-Japanese rapprochement; continuing division prevents any Japanese foothold on the peninsula. Korean tension with Japan is obviously rooted in memory and territorial issues, but antipathy toward Japan also serves a national identity-building purpose in South Korea. The ROK is trapped in a debilitating national legitimacy contest with the aggressively nationalist DPRK which does not hesitate to play powerful nationalist cards against the South: South Korea is Hanguk, while North Korea is Joseon. South Korea is the bastardized, globalized, 'Yankee Colony' selling Korea's heritage, folkways, and racial integrity to foreigners, while North Korea, despite its poverty, defends the minjeok against its many predators, including Japan and the US. To counter this narrative and the national confusion it generates, the ROK targets Japan instead of the DRPK as the focal point of its state-building nationalism. If the ROK cannot be the anti-DPRK, then it will be the anti-Japan. And China, especially under Xi Jinping, clearly manipulates Korean disdain for Japan. But when Korea unites, the anti-Japan animus needed for the intra-Korean competition will be unnecessary. The ensuing Japanese-Korean rapprochement would be a serious geopolitical set-back for China.

If points 1-3 are downsides to unification and strong reasons for China to prop-up North Korea, it should also be noted the North Korea has learned how to play on its 'buffer' role:

4. China's North Korean (quasi-)ally has a penchant for 'reckless driving.' That is, the DPRK does not follow Beijing's lead reliably. It is prone to rebuff and even slight Beijing to remind it that Pyongyang is still sovereign even if it is economically dependent. Both the nuclear tests in spite of Beijing's warnings and the brutal purge of Jang Sung Thaek seemed calculated, among other things, to remind Beijing that North Korea is not a colony or satellite. The obvious security cost for China here is that North Korea may one day go too far in its provocations and incur a South Korean or American counter-strike, which may in turn spiral into a conflict that chain-gangs in China. The DPRK may be a buffer, but is a highly unreliable ally.

To summarize, the buffer is the big reason, as best the panelists at the Korean unification conference last week could tell. There were four of us – me, plus two Koreans, and a Chinese. The two Koreans also emphasized this point, while the Chinese colleague was noticeably silent when pushed on this. This has been my experience before. I first started hearing Chinese conferees openly speak of the 'buffer' in 2009, but that seems to be fading, given how obviously manipulative it sounds.