Let me see if I have this straight.
After World War II, the United States occupies all of Japan.
In 1952, it ends the Occupation of the main islands but continues to occupy the Ogasawara Islands (the Bonin Islands, according to the Unites States Geological Survey) and the Okinawan Islands, including, at the time, the Senkaku Islands (the Senkaku-shoto, according to the U.S. National Geospatial Intelligence Agency) -- the last of which the U.S. Air Force and Navy use for bombing practice.
In 1968, the U.S. returns the Ogasawaras to Japan.
In 1972, the U.S. returns the Okinawan Islands, including the Senkakus, to Japan.
Now in 2012, the United States government says that it takes no sides on issue of sovereignty over the Senkakus.