Limits to China's influence

North Korea's continuing development of a nuclear and ballistic missile capability creates major headaches for Beijing, as well as for the rest of the international community.

While China has come in for some criticism for "not doing enough" to halt Pyongyang's programmes, its unhappiness with North Korea can be seen by its unusually forthright condemnation of the recent nuclear test. What is Beijing's policy in this area?

This is far from easy for China, as events on the Korean peninsula have a range of contradictory implications for its strategic interests. Firstly, China has no interest in a collapse of the North Korean regime.

This would either result in unpredictable chaos in North Korea, or to some form of unification, most likely with US or other western presence helping to shore up a new united Korea sitting on China's borders.

It would also bring major refugee flows into China's northeast. And China's position as North Korea's number one ally is not to be given up lightly, especially after Cold War competition with Moscow for influence.

The relationship between Beijing and Pyongyang in underpinned by a historical legacy of revolution and the symbolic importance of the Korean War to China.

Equally, China wants a peaceful regional environment and a non-nuclear Korean peninsula. This is not just because of the inherent risks associated with an unpredictable and independent-minded neighbour, but to reduce the possibility of other East Asian powers, particularly Japan, looking to develop a nuclear capability.

Beijing's recent strong language suggests this factor may be increasing in importance to Chinese policymakers.

And Beijing's wider international policy priorities demand a resolution of the crisis, hence a tougher line on Pyongyang.

China has made a point of describing itself as a "responsible power", which suggests a commitment to non-proliferation, and to working with other members of the United Nations Security Council on global problems.

Economically, good relations with Japan and South Korea have facilitated Chinese goals of development.

What about the domestic politics? We have no way of seeing inside China's hidden policy debates on North Korea. But given the seriousness of the issue, the lack of a clear route forward, and the wide range of conflicting Chinese interests involved, it is not unreasonable to assume that Chinese internal debates are characterised by divergent views, just as there are differences of view among politicians in the US and South Korean on how to deal with North Korea (it is partly the dead end created by the lack of policy options that has prompted western commentators to pressure Beijing to try and force a solution).

Any divergence of views within China is not necessarily along institutional lines, as ideological and strategic interests cut across different organisations.

But it is worth noting that the Ministry of Foreign Affairs has led the Chinese delegations to the Six-Party Talks, and it was a diplomat, the UN ambassador, who voiced the Chinese condemnation of Pyongyang's latest nuclear test.

The ministry is likely to favour an approach that speaks to China's responsible and peaceful diplomacy.

The military also has interests here, and if the reported June visit to China by Kim Jong-Il's "heir" did take place, it appears it was as part of a military delegation, with the Chinese People's Liberation Army (PLA) acting as hosts.

PLA views are particularly difficult to gauge, but tend to be hawkish, in particular when it comes to US military reach in East Asia.

However, they will certainly not want to have a nuclear-armed neighbour to China's northeast, particularly if this leads to an arms race in the region. This risk is growing rapidly.

Chinese policy on this is ultimately decided at the highest levels, with the secretive Central Military Commission probably the most important body in this process.

The signs of increasing Chinese diplomatic frustration with Pyongyang, combined with military nervousness over North Korea's capability, may reflect a shift in Chinese policy towards a more hardline position, perhaps initially through reasonably robust implementation of the latest UN-agreed sanctions.

But given the intransigence of the North Korean regime, there are limits to China's influence too. The headaches look set to continue.

Tim Summers, a former British diplomat is a researcher at the Centre for East Asian Studies, The Chinese University of Hong Kong.