Some assume the Japanese were like the Nazi or other European nations, when it was clear they could not win they would surrender. That was not true of the Japanese, the Japanese knew, as has been suggested, they could not win the war, but did believe America would tire of the casualties and arrange some type of peace where Japan would end up with territory that had her needed raw materials. With the Japanese philosophy of nation over death she would make every island, every inch of territory so costly in American casualties we would negotiate, and as we neared the mainland of Japan, Japan's resistance stiffened, hence the Iwo's and Okinawa's. We will never know how long Japan would have fought on, or how many more Americans would have died but we were given a choice, and we took it.
Thank you America