First, when those Island were invaded, the nuclear bomb was not ready yet. Second, it took a place in the main island for the bomb to be taken seriously.
Kyoto is just next to Osaka. Hiroshima is the largest island in Japan. It is in Kanto region ,under Shimane (if you know this place.) Nagasaki is in Kyushu. It is the feet of Japan. A little close to Okinawa.
at the red habin of england
In Japan you should visit Tokyo, Sapporo, Osaka, Kobe, Hiroshima, Nagasaki, Yokohama, Mt. Fuji, and Okinawa just to name a few.
Guadalcanal
The battle for Okinawa, had proven to be a small scaled example of what the invasion of Japan would be like. The decisions to drop the bombs, were largely based upon that battle.
South
Iwo Gima, Guadalcanal, Okinawa
Guadalcanal , Tarawa , Peleliu , Iwo Jima , Guam , Saipan ,
The driving distance is 697 miles.
Guadalcanal, Tarawa, Saipan, Guam, Okinawa, Tinian, Iwo Jima
If you are referring to "the" bombs, it sounds like you're referring to the two "Atomic" bombs that were dropped on the city of Hiroshima on 06 August 1945, and Nagasaki on 09 August 1945, thus ending WWII. If your referring to the Battle of Iwo Jima (where the US flag was raised), bombs and naval guns pounded that whole island.
The distance between Tokyo and Okinawa is 1,561 km (970 miles) or 843 nautical miles.