The following quote comes from Brigadier General Paul W. Tibbits, which I find interesting...

"The Enola Gay has become a symbol to different groups for one reason or another. I suggest that she be preserved and given her place in the context of the times in which she flew. For decades she has been relegated to a storage facility. Her place in history has been dealt with unfairly by those who decry the inhumanity of her August 6th mission. Ladies and gentlemen, there is no humanity in warfare. The job of the combatants, the families, the diplomats, and factory workers is to win. All had a role in that "all out" fight."

"...there is no humanity in warfare" speaks volumes. His speech, quoted here suggests pretty much in summary, he had a job, the President made a decision, he carried it out and he believes it was the right decision. He also says look forward. What's done is done.