Not many people get a bear-hug from Kim Jong-il, the North Korean leader, but Wen Jiabao, the Chinese premier, joined that club in October. This symbolic embrace signals a culmination of Chinese efforts to restore its relationship with North Korea following what Pyongyang calls “China's betrayal” in 1992 when Beijing established diplomatic relations with Seoul. Mr Wen's visit to Pyongyang to celebrate the 60th anniversary of Sino-North Korean relations underscores the importance, as well as the complexity of this strategic “friendship”. In contrast to the flurry of Chinese diplomatic activity, US ambassador Stephen Bosworth's visit yesterday to Pyongyang marks the first official contact between Barack Obama's administration and the North Korean regime.

Historically a buffer separating China from democratic South Korea, home to about 30,000 US troops, North Koreais also a key bilateral trading partner for China. Parts of China's north-eastern rustbelt are dependent on trade with North Korea, just as more than 70 per cent of North Korea's trade is dependent on China. This interdependence is growing, a trend having implications for US-led efforts to denuclearise North Korea.

As long as Pyongyang allows Chinese investments to continue, Beijing will encourage more companies to trade with North Korean partners. Beijing's goal is to keep the North Korean regime afloat. It is also seeking greater access to resources and to increase its influence over Pyongyang. The US has chosen an opposite tack: enforcing financial sanctions that many North Korea watchers believe have done little to change its behaviour. While both countries desiredenuclearisation, each country is pursuing a fundamentally different path to this goal.