I am willing to accept the reality of evil: the evil of killing innocent civilians. You don't get to complain about evil while trying to justify killing innocent people.
I'll mention that to 3 million Jews the next time I see them -
Who's trying to justify the Holocaust? It was evil for Hitler to go after innocent people. I'm sorry I hold the U.S. to the same standard, or higher since they purport to represent me.
You are NOT holding the US to a higher standard - you are creating a mythical criteria, ensuring it can't be met, and, thus, giving you a chance to pontificate from on high.
YOU say that "Truman was a bad guy for ordering the unnecessary vaporization of hundreds of thousands of innocent Japanese civilians" despite the fact that most historians agree that this action brought a quicker end to the war, and negated the need for a military invasion of the Japanese mainland, estimated to have cost another 500 - 750 thousand lives. (You'll notice I avoided embarrassing you by pointing out that, in fact, "hundreds of thousands" of Japanese weren't vaporized. The actual number was about 80,000. So, we traded 80,000 lives for 500,000 lives) Not everything is as black and white as you wish to paint it.
YOU say that FDR was 'bad' for putting an end to the WWII - even knowing that, had the war continued, many, many thousands more would have died.
I would suggest your problem is with your arbitrary definition of 'innocents'. Those who allow - or encourage - terrorism forfeit their innocence.