Beijing is no one's ally in the effort to pressure and disarm North Korea

Confident of the minimal risk of a North Korean collapse any time soon, China's principal concern is a potential thawing between North Korea and the West that could diminish its own economic and political influence, or lead to a US presence on its border.

In the coming weeks and months, Beijing will pull out all the stops to support the young Kim Jong-un and his coterie of elders in an attempt to cultivate influence. At a time when the world is more dependent on China's read of and influence on the regime in North Korea, China is the least likely to be forthcoming. Nor should the world expect that China will put any pressure on North Korea on its nuclear weapons programme.

Following the announcement of Kim Jong-il's death last month, China immediately turned its attention towards the reactions of the US and South Korea. Beijing summoned their diplomats to urge them to deliver supportive messages. Meanwhile, China sent its president, premier and vice-premier to the North Korean embassy to express condolences and invite Kim Jong-un to China. State media splashed anguished headlines that could have been mistaken for those in North Korean state media.

Beijing is redoubling efforts to shore up a regime that it knows the US and South Korea would rather see disappear. While in recent years China grew tired of providing Kim Jong-il with handouts - charging North Korea market prices for food - now it wants to be the one that Kim Jong-un turns to when he needs support to keep his loyalists onside. China could thereby strengthen its avenues of influence and access to information about the regime. But the West shouldn't expect to benefit from this.

In recent years, Chinese policy towards North Korea has increasingly diverged from US and South Korean aims on the peninsula. In 2008, after North Korea suffered a disastrous currency reform and Kim Jong-il faced a health crisis without a successor in place, China significantly strengthened its political, economic and military support to the authoritarian state. It did so with nary a word about denuclearisation.

In 2009, when North Korea launched a satellite, withdrew from the six-party talks and held its second nuclear test, China successfully diluted the UN Security Council sanctions. In testimony to how difficult it has been to get Beijing to implement them (like pulling teeth), Chinese diplomats refer to the US nuclear envoy that regularly travels to Beijing to discuss this issue as "the dentist".

In 2010, Chinese calculations on North Korea became more powerfully shaped by concerns about the US military and political presence in the region, reinforcing North Korea's importance to China as a strategic barrier against the United States and its allies. High-level displays of military solidarity with North Korea during the 60th anniversary of Chinese participation in the Korean war sent a message that China was willing to stand by its ally militarily as well as politically. Following the sinking of the South Korean naval ship Cheonan on March 26 and the shelling of Yeonpyeong Island on November 23, Beijing gave the rogue nation diplomatic protection while reserving its most strident criticism for US and South Korean military exercises.

Last year, China deepened its support to North Korea as part of a strategy to expand its economic interests and access to the country, while pressuring Pyongyang not to engage in deadly provocations that might give the US a pretext to expand its regional military presence.

Kim Jong-il visited China four times over 18 months and trade between the two countries soared (bilateral trade hit US$3.1billion in the first seven months of last year, an 87per cent increase from the same period the previous year). With a heavily reduced cash flow, severe food crisis and pressure on North Korea's leaders to deliver a "strong and prosperous" country by April, China's support became an economic lifeline for Pyongyang.

Those in China critical of its support to its reclusive neighbour have become increasingly marginalised, while the key Chinese institutions in charge of North Korea policy - the conservative International Department of the Communist Party and the army - are the least likely to engage with outsiders on contingencies, let alone with North Korea's avowed enemies.

Chinese economic actors complaining that investment in North Korea is money down the drain have been told to keep their eyes on the prize: preventing reunification and a US-allied nation on China's doorstep.

Nationalists are given wide platforms to criticise what they see as the Americans' use of events in the region to encircle and contain China. Recent announcements concerning America's pivot to Asia, the deployment of 2,500 US marines in Australia and US Secretary of State Hillary Rodham Clinton's visit to Myanmar have strengthened these voices.

At a time when the world is arguably most dependent on China's read of the situation in North Korea, Beijing's national interests diverge seriously from Washington's. Those in the West hoping or expecting meaningful co-operation with Beijing are bound to be disappointed.