Four decades ago China agreed not to press its territorial claim on the tacit understanding that Japan would not settle or build on the rocky islets. Every now and again nationalist activists from Hong Kong or Japan would land on one of the islands and plant a Chinese or Japanese flag; there was an angry showdown two years ago when Japan arrested a Chinese fishing boat captain. But the status quo prevailed.
Everything changed on Sept. 11 this year, when the Japanese government purchased three of the islands from their private owner. Chinese leaders and media reacted with fury, spurring demonstrations in scores of cities, some of which turned violent, with people looting and torching Japanese-owned businesses.
In vain did Japanese officials try to explain that Prime Minister Yoshihiko Noda had "nationalized" the islands to keep them out of the hands of the governor of Tokyo, a nationalist firebrand who was trying to buy them, likely to use them to provoke China.
Beijing declared its "base lines" around the islands, defining the exact area of its territorial claim, as the legal basis on which it claimed jurisdiction, and began sending surveillance vessels and, in one instance, two naval frigates, within 12 miles of the islands, into what Japan claims as its territorial waters.
"These patrols change the fact of only Japan controlling the islands," says Professor Liu. "Japanese administration and management will no longer be a reality."
At the same time, the Chinese Navy and Air Force staged joint drills in the East China Sea, not far from the disputed area, and the vice chairman of China's Central Military Commission, Gen. Xu Caihou, publicly urged the Army to "be prepared for any possible military combat," the state news agency Xinhua reported.