"Tokyo, however, is under intense political pressure to keep the noise problem and danger of crashes as far from the public as possible. More than 700 miles off Japan's main island, Iwo Jima, long inhabited only by Japanese soldiers, fits that bill. "
http://www.military.com/NewsContent/0,13319,FL_japan_071504,00.html
I can only imagine what kind of problem a fuel and weapons laden f18 would pose the any neighborhoods it might happen to drop out of the sky on.