No, a bomb didn't solve WW2. That's an incredibly inaccurate statement. The dropping of the atomic bombs was completely un-needed, and even the uranium club along with those who made the original atomic bomb generally agreed that these weapons should not be used, and they should be disarmed. The ONLY REASON we dropped the atomic bombs instead of invading was because it would have caused the death of more soldiers than needed. The Pacific theater was ending, and the push to the mainland was progressing even further. Japan was on the defensive, and we simply ended it. The bomb did not solve World War 2, in fact it could have been solved in many other ways. If Japanese soldiers were not so bent on never surrendering, World War 2 would have probably ended after the battle of Leyete Gulf, in fact by this time we were already doing Air Raids over Japan, Thailand, and Korea.
But on the actual subject, hundreds of thousand of innocent civilians were killed in a span of 5 years, and still are today through drone strikers. For every 1 terrorist that dies, 50 other civilians are killed as well.