Things to Worry About: Japan and China and some islands in the East China Sea

Daniel Blumenthal at Foreign Policy's Shadow Government blog, on "Why the Japan-China Senkaku dispute is the most explosive issue in Asia":

While the United States affirmed that the U.S.-Japan treaty covers the Senkakus, there still is a disagreement between Washington and Tokyo over who has sovereignty over the islands. This disagreement dates back to the 1970s and is yet another manifestation of the careless and rushed way in which Washington handled its normalization with China.

Arrow indicates disputed area. Sea lanes in purple (from CIA map).

Update: Another effort to show the disputed area

Japan feels isolated, and cannot understand why Washington remains neutral over this sovereignty dispute. Japan has a point. The United States has dined out on a neutral stance -- falling back on apathy toward the outcomes of territorial disputes throughout Asia, as long as they are "resolved peacefully" -- for a long time. This position was reasonable enough when China was weak and unable to press its claims, but those days are over. Is the United States really agnostic about the outcome of territorial disputes in the East and South China Seas? Of course not. It does not want conflict, but neither does it want China to control territories that sit along important sea lanes.

Of course, sea lanes are vital, but as noted here: