It's actually interesting what it brought forth, it made Japan the leader in the anti-atomic movement, but more interestingly Japan also made itself the only country that truly knows what Armageddon is. Little Boy and Fat Man is the indirect cause to story's like Nausicaä of the Valley of the Wind and Akira. It's why Armageddon story's are so common in Japan. It's also why a movie like Blade Runner has a Japanese setting. In a way September 6 - 08:15 has been a reset button for Japan. The new year zero if you will. From that point on Japan changed rapidly. Many then saw the atomic bombing as the point were Japan needed drastic change, of course also spurred by the American occupying the country for several years. But is was not only the American who thought Japan needed the change many Japanese themselves felt so.
On the subject itself, I think it was necessary evil, and yes it does exist. Even in Japan itself many see it that way. Not only did it end the War it also ended the Military Dictatorship. It's also the reason Japan doesn't really blame America, they don't point fingers at them. They just acknowledge nuclear weapons are horrible and should never be used again.
