LogFAQs > #975290934

They did warn the Japanese. The Japanese government chose not to warn their civilians.

It was also new tech, there was no guarantee that it wouldn't have failed, making a demonstration or direct advanced warning potentially disastrous had it gone wrong.

There was also divided mistrust on if Japan was close to surrender or not. Some thought they were close, but others couldn't get over the brutal defense of Okinawa, Iwo Jima, and Manila out of their heads and couldn't believe that that military was really ready to stand down.

Also, anyone saying that he did it because he was racist are really ignoring the fact that we absolutely would've had no problem nuking Germany at that time. We were flattening cities left and right in Germany and Japan already, the nuke was just a much more efficient means of doing so (with the lack of understanding that they had regarding fallout, I mean). Traditional bombing of Tokyo killed more and the bombing of Dresden killed almost as many as a nuke.