The current dispute focuses on the Senkakus (known by China as the Diaoyus), a group of small uninhabited islands approximately equidistant between mainland China and the Japanese island of Okinawa. Beijing and Tokyo both claim sovereignty over the islands. But Japan has exercised continuous administrative control over the islands since the U.S. returned control to the Japanese in 1972.
Beginning in the fall of 2012, China began to actively challenge Japan’s claims to uncontested sovereignty by conducting Coast Guard patrols near the islands, sometimes supported by a People’s Liberation Army (PLA) naval presence. In November 2013, China upped the ante by declaring an Air Defense Identification Zone (ADIZ) that included the Senkakus, prompting added concerns about the potential for a direct clash between East Asia’s two major powers.
Read more: http://www.brookings.edu/research/opinions/2014/02/25-mission-action-2013-jpollack?rssid=asia+and+the+pacific&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+BrookingsRSS%2Ftopics%2Fasiaandthepacific+%28Brookings+Topics+-+Asia+and+the+Pacific%29