According to recent news reports, a growing group of Chinese officials and scholars has commenced a semiofficial campaign to challenge Japanese sovereignty over Okinawa. This is of course in addition to the widely publicized Chinese efforts to challenge Japanese control over the Senkaku / Diaoyu Islands. The basis for the claim to Okinawa appears to be a combination of early history and the Cairo Declaration, which the United States, China, and the United Kingdom issued in 1943 to help prepare the post-war order in East Asia. The argument goes like this: Okinawa and the other Ryukyu Islands were originally Chinese territory because the Ryukyu Kingdom was a tributary state of the Ming and Qing Dynasties; Japan stole the Ryukyus by invading them in 1609 and formally annexing them in the late 1870s; the Allies demanded the reversion of sovereignty over Okinawa to China in 1943 by stating in the Cairo Declaration that “all the territories Japan has stolen from the Chinese . . . shall be restored to the Republic of China”; and Japan agreed to the reversion of sovereignty by accepting the 1945 Instrument of Surrender, which provided for the enforcement of the Cairo Declaration. In this post, I’d like to identify a few reasons why this argument is unpersuasive.

First, it is at best questionable that China had original sovereignty over Okinawa. The Ryukyu Islands were never part of China proper; they maintained a separate government and leadership, and had their own languages and cultures. While Okinawan kings paid tribute to Chinese dynasties and received investiture missions from China, so did much of East Asia, including Korea, Thailand, and Vietnam, among others. These territories were not part of China in the sense that California is part of the United States, or England is part of the United Kingdom. To say that they were exaggerates China’s historical power. Okinawa’s relationship with Satsuma—one of the feudal domains of early Japan—amply illustrates the point. Even while paying tribute to China, Okinawan kings swore oaths of allegiance and paid annual tribute to Satsuma, which in turn exercised substantial authority over Okinawan political and economic life, including by regulating the importation of weapons, making final decisions in judicial cases involving the death penalty or exile, regulating Okinawa’s trade with China, and deciding succession to the throne. These acts of authority, some of which date back to the sixteenth century, are extremely difficult to reconcile with the idea of Chinese sovereignty in the Westphalian sense.

Second, even assuming original Chinese sovereignty over Okinawa, the Chinese nationalist claim seems to disregard the international law doctrine of acquisitive prescription, which holds that one state can obtain title over part of the territory of another by asserting effective control in a peaceful and public manner, without interruption, for a sufficient period of time. As far as I know, China hasn’t objected to Japanese sovereignty over Okinawa for well over a hundred years. If anything, it has done precisely the opposite: official Chinese maps and documents have repeatedly depicted Okinawa as Japanese territory. This acquiescence has enabled Japan to hold Okinawa without interruption. While the United States exercised administrative authority over the Ryukyu Islands from 1952 to 1971, we did so on the understanding that Japan retained “residual sovereignty.” It’s hard to think of an easier case for acquisitive prescription.

Third, it is doubtful that the Cairo Declaration granted sovereignty over Okinawa to China. The reasons are numerous. For starters, the Declaration did not purport to establish a final territorial settlement; the Potsdam Declaration, which the same states issued only two years after Cairo, explicitly left the extent of Japanese sovereignty over “minor islands” for future determination. If the Allies had understood Cairo to be the final say on the matter, there would have been little reason to address the issue again at Potsdam or in negotiations over the San Francisco Peace Treaty. Additionally, there is to my knowledge no evidence that the signatories of the Declaration intended to grant Okinawa to China. The Declaration, after all, said nothing about Okinawa even while mentioning the far less substantial territory of the Pescadores.

Finally, on a less legalistic note, I lived in Okinawa for about a year in my early twenties. Based on that experience, my sense is that the idea of Chinese sovereignty over Okinawa would be surprising, and probably upsetting, to most Okinawans today. While many residents are resentful of Tokyo’s agreement to locate major U.S. military bases on the islands, they all speak Japanese, watch Japanese TV, celebrate Japanese holidays, and travel to mainland Japan for education and business. Island residents think of themselves as Okinawan, rather than Japanese, but are in a wide variety of ways fully assimilated into modern Japan.

The history between Japan and China is incredibly complicated and sensitive and impossible to reduce to a few paragraphs, but I think there are a couple of tentative observations to make about the nascent Chinese nationalist campaign for Okinawa, given the preceding legal analysis. One is that Chinese nationalism is a nostalgic ideology in the sense that it downplays or simply disregards modern demographic and legal realities while relying heavily upon the Sino-centric East Asian order of the Ming and Qing Dynasties as the foundation for audaciously expansive territorial claims. The other observation is that the borderline frivolousness of the Chinese nationalists’ claim to Okinawa weakens the credibility of their claim to the Senkaku / Diaoyu Islands. If these individuals are asserting Chinese title over Okinawa notwithstanding the apparent absence of legal support, what’s to say that they take international law seriously in claiming the Senkaku / Diaoyu?