The wave of anti-Japanese protests that swept across dozens of cities in China this weekend, prompted by Tokyo's purchase of three disputed islands, has obscured a potentially more worrying development that risks drawing the two countries into a larger conflict: China's adoption of a legal framework empowering it to expel foreign vessels in disputed waters in the East China Sea.
The most recent round of tension between the world's second- and third-largest economies reached a new height last week when Japan announced that it was finalizing the purchase of three of five uninhabited East China Sea islands -- which Japan calls the Senkakus and China calls the Diaoyus. While the move was intended to prevent the hard-line, nationalist Tokyo governor from purchasing them himself, that distinction was apparently lost on Beijing, and Tokyo's timing couldn't have been worse.
China reacted quickly to what it saw as Japan's reaffirmation of its sovereignty claim with a variety of measures, which state media called "combination punches." These ranged from Politburo members strongly denouncing Japan to Prime Minister Wen Jiabao vowing to "never yield an inch" to threats of economic retaliation to announcements of joint combat drills by China's navy, air force and strategic missile corps, including landing exercises in the Yellow Sea and the Gobi Desert.
But a quieter move may have more serious repercussions in the end. On Sept. 10, China's Ministry of Foreign Affairs announced baselines to formally demarcate its territorial waters in the area. In Beijing's eyes, this move legally places the disputed islands under Chinese administration in a direct challenge to Japan's administration of the islands over the last four decades. Since the islands reverted to Japanese government control in 1972, they have been administered by Japan.
This move is a departure from China's previous policy of seeking joint exploitation of resources with Japan through negotiation, and also differs from China's approach to the South China Sea, where it has maintained calculated ambiguity with regard to its claims by not fully clarifying how much of the area China actually claims as its own.
Such an unprecedented move to formalize its claim of the contested territories obliges China under its own laws -- and in the court of domestic public opinion -- to assert jurisdiction over the waters surrounding Diaoyu. Almost immediately after the new baselines were declared, China sent six Chinese Maritime Ocean Surveillance vessels into disputed waters on what the Foreign Ministry said was a "rights defense law enforcement action." Not to be outdone, China's second-largest maritime law enforcement agency, the Fisheries Administration, announced plans to patrol the disputed waters, starting with protection of 1,000 Chinese fishing boats that have just left for the area.