On February 7, U.S. Secretary of State John Kerry reaffirmed the U.S. commitment to the promises made in the "Japan-U.S. Security Treaty" signed in 1960. He emphasized that the commitment "included the East China Sea." It is believed that the speech was focused on the Diaoyu Islands. In an interview with CCTV, Sun Zhe, a Professor at the Institute of International Studies of Tsinghua University, stated that the U.S. misjudgment of the situation may cause the Sino-Japanese dispute to turn into a military conflict between China and the U.S.
Sun Zhe pointed out that, in the past, the United States would use the names of both the "Diaoyu Islands" and the "Senkaku Islands" when referring to the Diaoyu Islands in a written document. Now, however, only the latter is used. In addition, the United States is concerned about China’s cruise surveillance at the Diaoyu Islands. The U.S.’s protection and support of Japan has become more evident. This is the equivalent of [the U.S.] "choosing sides." This could make Japan misjudge the situation.
Sun further pointed out that the United States assumes it needs to mediate as a judge when friction results in an accident. It makes the assumption that, if something happens in the Diaoyu Islands, the U.S. and Japan will act together and it will send troops to help Japan seize de facto control [of the islands]. This would be a misjudgment of the situation. It may turn the Sino-Japanese dispute into a military conflict between China and the U.S. and cause a lot of damage to the building of new China-U.S. relations.
Source: People’s Daily, February 10, 2014