Because we don't have the same leadership we had with Truman and some of the other presidents before him. The leaders of today don't have backbone. They're spineless. The Democrats are even worse.
The Japanese would not surrender. The Islamics are about the same if you are doing an analogy of fanaticism. Hiroshima was A-bombed and women, little children, babies, dogs, cats, birds, bugs and snakes (along with a few fighting men) were killed. It had to be done. It was horrible, but it had to be done. Nagasaki was also nuked. The same demographic died. Yes, it was horrific and sad. Japan finally surrendered.
We have simply got to have the will to take a place like Fallujah off of the face of the map with a nuclear weapon. And, if that doesn't work, then Najaf. Or, Karbala, etc. It won't take but two or three maximum before the radicals decide it's not worth it. I DON'T care what the world thinks. The vast majority of the world hates us fervently anway. As someone so aptly posted some time ago...can't remember who said it, "Let them hate us so long as they fear us." It is time to do something to bring the fear of God to the people of the world. Now is the time. Where is our leadership? Where?
Comparing this current situation in Iraq with Japan in 1945 is a bit extreme. We had lost quite a bit more than 700 soldiers in 1945 before we decided to drop the 2 bombs before an invasion. We'd have to nuke America if we wanted to start killing terrorists. Are you prepared for that?