you seem to overlook something pretty obvious. Japan didn't surrender after the Hiroshima bombing. They finally surrendered several days later after Nagasaki was bombed. If they didn't surrender after Hiroshima, what makes anyone think they'd surrender after a demonstration? After all, what more effective demonstration is there than the actual destruction of a city?

There is a lot of controversy about the atomic bombings. Between the submarine blockade and the fire bombing attacks, many say Japan was on the ropes. According to several sources, we intercepted Japanese diplomatic instructions to have their ambassadors in Europe sue for peace days before the bombs were dropped. Some say the actual target for the bomb was to serve as a demonstration to Joe Stalin. Others point out that had Truman not dropped the bomb to end the war quickly, he likely would've been impeached. After all, the US spent over $2 billion (about $20 billion in today's dollars) developing the bombs.

There was a good program on the History Channel over the weekend about how the war would've ended had we not dropped the bombs and Japan not sued for peace. Our forces were scheduled to invade the southern Japanese island of Honshu on Nov 1, 1945. The forces were going to take over about 1/3rd of the island and use it as a launching point for the invasion of the Tokyo plains about 6 months later. The Japanese military leaders knew exactly which beaches would've been used for the invasions and had prepared a very hostile welcome. Based on their defense of Iwo Jima and Okinawa, we likely would've suffered losses of several hundred thousand personnel.

There is an interesting little historical footnote to all of this. As part of the planning phase for these invasions, some bureaucrat ordered over 300,000 Purple Heart medals to be awarded to the expected casualties. Fortunately, those medals weren't needed for WWII. As a result, every Purple Heart awarded since WWII was part of that batch of medals ordered for the Japanese invasion. There were more than enough medals to cover all of the casualties from the Korean War, Vietnam, the Gulf War, and all of the other little operations since 1945.