The abandonment of a large investment by Chinalco in Rio Tinto leaves the Chinese state-owned group smarting and a question mark over the Beijing government's strategy of scooping up natural resources around the world. This is a good point at which to affirm a policy in favour of open global markets for commodities.

Putative Chinese investments abroad sometimes face a reaction of knee-jerk nationalism. The west should instead assess them with pragmatism. This is especially true for countries that rely on Chinese money to fund their external deficits. Companies accepting Chinese equity stakes are surely no greater cause for worry than governments depending on Chinese credit lines.

But this does not mean there is no cause for worry at all. China's government is making a co-ordinated effort to buy up resources while they are cheap. While there is nothing inherently reprehensible in that goal, the question is whether the world – and the Chinese – will benefit from the way it goes about this. Most fundamentally, China must decide whether it will help strengthen markets or undermine them.