Japan's decision to purchase and nationalise three islands in the East China Sea has caused protests to erupt in more than 100 Chinese cities. The islands sit within a grouping known as Senkaku in Japan and Diaoyu in China, which is the subject of a long-running sovereignty dispute. As well as stirring deep nationalist emotions, the argument is important because of the potential for exploitation of undersea resources.
Beijing reacted swiftly to the Japanese move, putting economic pressure on Japanese businesses operating in China and embarking on fresh legal attempts to claim the islands for itself. But it stopped short of a military response and instead deployed maritime paramilitary vessels to the islands, suggesting that it was seeking to avoid a military confrontation, for the time being at least.