In the run up to its first party congress since 1980, the North Korean government increased its drive to develop nuclear weapons, raising tensions in the region. This has alarmed and angered neighbouring countries, and particularly China, whose president Xi Jinping made clear at a recent conference that China will not tolerate chaos on the Korean peninsula.

At the same time, many outsiders suggest that Beijing’s close relationship with Pyongyang means that China has a crucial role in reining in North Korea – and that it could do so if it really wanted to.

US President Barack Obama called on China to increase its pressure on North Korea, after North Korean leader Kim Jong-Un hailed a submarine-launched ballistic missile test as an “eye-opening success”. A few days later, Obama’s aspiring successor Donald Trump vowed to push China to take more responsibility for North Korea if he makes it to the White House. China could be pushed to do so, he suggested, if the US threatened to otherwise plunge China into recession by withdrawing American business.

Mr Trump may or may not be right that the Beijing leadership is dragging its feet on North Korea. But if he is, what are the reasons why the Chinese leadership might act in this way?

To try and understand this, it’s not enough to think about the national interests of the Chinese state; it’s also crucial to think about the political interests of the Chinese Communist Party (CCP) itself.

The days are long gone when the CCP could claim to represent the interests of China’s revolutionary classes. It abandoned any pretence of this in the early 2000s under the last president, Jiang Zemin, whose “Three Represents” policy explicitly incorporated bourgeois and capitalist classes into the party. The government now claims to represent instead the “overwhelming majority of the Chinese people”.

This is a concession to political reality: to retain the general population’s consent to one-party rule, the CCP leadership has come to rely on the twin forces of economic growth and nationalism.

Stability and growth

The party’s main source of legitimacy is economic growth, the rationale being that China’s people will accept the Communist Party’s grip on power as long as their living standards continue to improve. That growth is dependent on a peaceful East Asia.

This is a key reason why China backed significant new UN sanctions against North Korea, despite being one of its neighbour’s few allies. President Xi reinforced that message in a speech to regional foreign ministers on the eve of Pyongyang’s party congress: “As a close neighbour of the peninsula, we will absolutely not permit war or chaos on the peninsula. This situation would not benefit anyone.”

But even putting stability aside, a range of other scenarios on the Korean peninsula could jeopardise Chinese growth. North Korea is an important source of the high-grade coal that powers Chinese industry, which is in turn the foundation of its international trade. Beijing appears to have implemented the sanctions by banning imports of North Korean coal, but it remains to be seen whether widespread smuggling will continue as it has in the past.

China is responsible for buying about 90% of the north’s exports, and cutting off that income stream could greatly exacerbate the already terrible poverty and famine that blight North Koreans’ lives. The result could be a wave of destitute North Korean refugees. There’s little doubt where they would head – and Beijing knows that dealing with a refugee crisis is not cheap.

It is therefore little surprise that while Beijing is very annoyed with Pyongyang’s unpredictable sabre-rattling, it still opts for caution and moderation.

Image management

North Korea is also a threat to the party’s other main source of legitimacy: popular nationalism, an unwieldy tool that can easily be turned against its users.

The key to keeping nationalist opinion on the regime’s side has been the cultivation of an image of benevolent leadership, both at home and abroad. Such an image can help counter the so-called “China threat theory”, a school of thought that views China as a risk to the international order, and can help turn global popular opinion in Beijing’s favour. That can in turn boost both international trade and the Chinese people’s pride in their considerate leadership.

To preserve this reputation, Beijing needs to present itself as the good and peaceful alternative to meddling Western powers, particularly a bellicose and interventionist US. But on this point, it seems to have expended a good deal of capital.

The worst factor is the long-running diplomatic tussle over contested areas of the South China Sea, where Beijing is engaged in a territorial dispute with a number of its neighbours. These projects have provoked China’s neighbours, and made many afraid that China is setting out on a more assertive and expansionist path. Beijing claims that the massive runways it has built on tiny islands are for civilian purposes, and blames the US for militarising the sea, but onlookers are unconvinced.

The Chinese Communist Party therefore has good reason to tread carefully in its North Korea policy, and to refrain as far as possible from anything perceived as the sort of pernicious meddling for which Pyongyang is always condemning Washington. Xi Jinping and his government know that happens in North Korea might not only decide the security and prosperity of the Chinese state and its people, but that it might also determine the fate of the Chinese regime itself.