China reacts with surveillance ships to Japan's purchase of disputed islands

China sent six surveillance ships into waters near disputed islands in the East China Sea on Friday, but quickly withdrew them in a sign that Beijing does not want tensions with Japan to rise too sharply.

The civilian vessels were engaged in “the normal performance of their duty,” Chinese Foreign Ministry spokesman Hong Lei told reporters. The ships withdrew soon after being ordered to leave the area by Japanese coast guards, Japan’s Kyodo news agency reported.

The sovereignty dispute has flared up again since Tuesday, when the Japanese government purchased three of the five contested islands from the Japanese family that had owned them. The uninhabited islands are known as the Diaoyu in China and as the Senkaku in Japan.

Beijing clearly had to react, if only because popular sentiment is running high on the issue in China; protestors have staged demonstrations in a number of cities, Japanese citizens have been assaulted on the streets of Shanghai, tempers are flaring in Internet posts and nationalism is rampant.

Aside from that, the islands could also be valuable; ownership of them gives rights over rich fishing grounds and a claim to potentially huge oil reserves under the nearby seabed.

Senior Chinese officials have limited themselves, however, to strong words and saber rattling. Today’s edition of the “People’s Daily,” the ruling Communist party’s official organ, carried a full page article detailing China’s recent military modernization program, for example.

On Thursday, in a thinly veiled hint at retaliatory economic steps, Chinese Vice Minister of Commerce Jiang Zengwei told a news briefing that "with Japan's so-called purchase of the islands, it will be hard to avoid negative consequences for Sino-Japanese economic and trade ties."

Behind the bluster, though, it might well be that Beijing has decided privately to accept the Japanese government’s explanation that it bought the islands to prevent further trouble.

Shintaro Ishihara, the stridently nationalist governor of Tokyo, had announced his own plan for the Tokyo municipality to buy the Diaoyu/Senkaku islands. Had he done so he could have caused untold mischief, provoking the Chinese at will by starting to build, or even to settle people.

Still, the sight of a Japanese citizen selling the islands to the Japanese government, regardless of China’s insistence that they are not anybody else’s to sell, has been painful here.

The authorities have salved their national pride with gestures. Last Tuesday, China began issuing weather forecasts for the islands and their surrounding waters, after publishing baseline coordinates setting out the Chinese view of which bits of rock and water belong to Beijing.

Eventually, tensions will doubtless fade, China and Japan will quietly acknowledge that they can never resolve the issue of sovereignty, and both sides will end up doing some sort of resource-sharing deal, just as they have elsewhere in the East China Sea. But that might take a while.