By Kathrin Hille in Beijing and Mure Dickie in Tokyo
For many observers, rising frictions between China and Japan over a group of remote and uninhabited islands in the East China Sea are worrying enough.
But if some influential Chinese nationalist commentators have their way, the spat over the Japanese-controlled Senkaku islands – which Beijing calls the Diaoyu – could widen into a dispute over a much more important archipelago.
In a fiery editorial earlier this month, the Global Times newspaper urged Beijing to consider challenging Japan’s control over its southern prefecture of Okinawa – an island chain with a population of 1.4m people that bristles with US military bases.
“China should not be afraid of engaging with Japan in a mutual undermining of territorial integrity,” the Communist party-run paper declared.
Major General Jin Yinan, head of the strategy research institute at China’s National Defense University, went even further. He told state radio that limiting discussion to the Diaoyu was “too narrow”, saying Beijing should question ownership of the whole Ryukyu archipelago – which by some definitions extends beyond Okinawa.
While the Chinese government has offered no endorsement of such radical views, their open espousal by senior commentators is likely to be deeply unsettling both to Japan and other neighbouring nations.
“Challenging Japan’s sovereignty over the Ryukyus would indeed be a break from the past,” says Taylor Fravel, a Chinese security expert at Massachusetts Institute of Technology, who argues that Beijing has tended to limit its territorial claims for the sake of clearly defined borders.
Chinese questioning of Japanese sovereignty over Okinawa is based on the prefecture’s roots in an independent state known as the Ryukyu Kingdom that won control of the archipelago in the 15th century.
Ryukyu kings paid formal tribute to Chinese emperors, a practice allowing lucrative trade that continued even after the kingdom was conquered by a Japanese feudal domain in 1609. Okinawa only officially became part of Japan in 1879.
For some in China, this history is enough to render illegitimate Japanese rule over a strategically important archipelago seen as the biggest impediment to the expansion of Chinese naval power in the Pacific.
Tang Chunfeng, a former official at the Chinese embassy in Tokyo, is one of those campaigning for China to rethink its acceptance of Japanese rule over Okinawa, saying past restraint has “done a lot of harm”.
“When I was in Japan, I didn’t even know that the Ryukyus were once ours,” says Mr Tang, now a Japan specialist at a commerce ministry think-tank.
But such arguments could be diplomatically incendiary.
“Once you start arguing that a tributary relationship at some point in history is the basis for a sovereignty claim in the 20th century, you start worrying a lot of people,” says June Teufel Dreyer, a China and Japan specialist at the University of Miami. “Many, many countries had tributary relationships with China.”
Some Chinese hawks stop short of saying Okinawa should be Chinese, suggesting it is enough to promote the idea that the archipelago should be independent from Japan. Such a gambit, they say, would make clear to Tokyo the cost of continuing to deny Chinese claims to the Diaoyu/Senkaku.
But Zhou Yongsheng, professor at China Foreign Affairs University, warns against such tactics.
“Using the Ryukyu sovereignty issue to resolve the Diaoyu dispute would destroy the basis of China-Japan relations,” Mr Zhou says. “If this was considered, it would basically be the prelude to military action.”
Nor can Beijing expect much enthusiasm for independence among Okinawans. While many in the prefecture are unhappy with Japanese government policies – and with the presence of US troops – separatist sentiment is muted. A pro-independence candidate who ran for governor in 2006 received only 6,220 votes.
Chinese questioning of Japan’s sovereignty over Okinawa, would also invite comparisons with Beijing’s own policy of suppressing pro-independence movements among its much more restive Tibetan, Mongolian and Uighur populations.
Yasukatsu Matsushima, a professor at Ryukoku University in Kyoto, is a strong advocate of Okinawan independence who believes Tokyo’s rule over the islands is illegal, but he notes that at least in Japan such views can be openly expressed.
It would be “strange” if China supported self-determination for Okinawans but continued to deny it to its own minorities, Mr Matsushima says.
“We have to consider the background [to any Chinese support for independence],” he says. “We can’t allow Ryukyu independence to be used as a tool.”