A hawkish Chinese general has possibly opened a Pandora's box on territorial disputes in East Asia by saying that the Ryukyu Islands including Okinawa do not belong to Japan.
Luo Yuan, a People's Liberation Army two-star general, has said that Japan could not rightfully claim sovereignty over the islands, because they had started paying tribute to China half a millenium before they had done so to Japan.
The islands had started paying tribute to China in 1372, the general said in an interview with China News Service  on Tuesday. Only in 1872, 500 years later, did Japan exploit China's weakness to force the Ryukuyu Islands into submission, he said.
Okinawa, the chain's largest island, hosts several US military bases. The islands were controlled by the United States under a UN mandate until 1972, when they were handed over to Japan.
The general, known for his outspoken nationalism, reasoned that the Ryukyuan people had closer ethnic and cultural ties to coastal China than they had to Japan. Their rulers were vassals of the Chinese court, he argued.
The People's Daily, the official newspaper of the Chinese Communist Party, and a magazine published by the Chinese Ministry of Foreign Affairs recently questioned Japan's sovereignty  over the island chain with a population of 1.4 million.
"Let's for now not discuss whether [the Ryukyu] belong to China, they were certainly China's tributary state," said the major general. "I am not saying all former tributary states belong to China, but we can say with certainty that the Ryukyus do not belong to Japan."
The People's Republic has had a contradictory record on making its territorial claims based on imperial China's tributary relationships.
Territorial claims in Tibet, Xinjiang and Inner Mongolia have led to now rarely disputed sovereignty. Until this month the Ryukyus - although once linked to imperial China through symbolic tribute - have not been included in such public debates over sovereignty.
Luo's comments come as a territorial dispute over the uninhabited Diaoyu Islands between Taiwan and the Philippines has mobilised nationalists in both countries and brought diplomatic relations between Beijing and Tokyo to a virtual standstill.
"The Ryukyus don't belong to [Japan], how can we even talk about the Diaoyu Islands," Luo said.