The greatest challenge of handling North Korea is not so much the highly volatile, unpredictable nature of the country itself. Were a country with the political system and behavioural traits of North Korea to be located, for instance, in Africa, or Central Asia, or even Latin America, it would be far less problematic. The greatest issue is that it sits right next door to China, the world’s great emerging power, and acts as a frontier between Chinese ambition and its reach into the wider world and US constraint.
Seen in this context, Donald Trump blithely telling President Xi Jinping that if the Chinese cannot deal with North Korea, then the US unilaterally will, is an incendiary comment. It is as good as Trump saying that the US intends to intervene directly in China’s internal affairs. And while North Korea is a sovereign nation, in many ways it acts as an honorary adjunct to China. In official discourse, after all, the two say that they are like 'lips and teeth' with each other.
There are lots of reasons for this closeness. Firstly, North Korea is the only country that has a security treaty with China. This commits China to consider defence of North Korea in a similar way as the US needs to take care of its treaty alliances throughout the rest of the Asia-Pacific region.
Secondly, its maintenance of a Communist system, however eccentric and unique, means there is still a political kinship between China and its small, impoverished neighbour. They have a shared history of sacrifice and anti-colonial struggle. That gives them an emotional bond that many underestimate at their peril.
Finally, and perhaps most importantly, North Korea might be distasteful and irritating to China, with its constant blackmail and provocations. But as so often in diplomacy, the key thing is location, location, location. North Korea occupies absolutely key strategic territory. A US creeping into this space would be simply unacceptable for China. And on this issue it has form. Even at a hugely sensitive and unstable moment in 1950, soon after the People’s Republic was established, China fought a costly, bitter war against UN forces to ensure that North Korea was not subsumed within a Korean peninsula under US hegemony. It is now in a very strong position to ensure that this does not risk happening again.
For all the sound and fury of Trump’s words in his interview with the Financial Times before Xi’s US visit, he is stuck in the same position as his predecessors – needing to find ways of putting pressure on the Chinese to use their unique leverage of North Korea to enforce some kind of positive change there. There is no doubt that China, were it to withdraw supplies of energy and aid to its neighbour, would stand a good chance of toppling the regime in a matter of weeks. Underneath all the North Korean ploys and games, they are economically no more than a Chinese vassal state. It is only extraordinary manipulative, brutally Machiavellian diplomatic behaviour that has kept them afloat.
North Korea, a desperate country with no real plan B, is utterly aware of this ability it has to play the two great powers off against each other. It has manipulated both, through its nuclear programme and other ploys, for the last two decades, bandwagoning as befits its aims. If Trump can at least get some common ground with the Chinese on how to jointly restrain, and mitigate, some of North Korea’s more bellicose and exploitative actions, he will had done well.
But threats of unilateral action will not do the trick. In fact, they stand a chance of achieving exactly what Pyongyang wants – stark division between its external foes and, perhaps, real conflict.
Kerry Brown is professor of Chinese Studies and director of the Lau China Institute at King's College, London.