Just my 2 cents as yet another American citizen reading this. I concur that it's irritating to be grouped with others based on my country of residence. Just because I inhabit the same nation doesn't mean I'm automaticaly going to be of the same mind as the kinds of individuals that have said such hateful and misinformed things. Every conceivable collective group has its share of morons. As an example, just look at the trouble with Islamic terrorists. The vast majority of Islamic believers are fine individuals, but zealous extremists cast their shadow over the whole group.
On the issue of the bombings of Hiroshima and Nagasaki, I dont think it's appropriate of me to say that it counted as payback. I might use a term like that if it were a situation akin to playing pranks. You fool me, I fool you back, and around it goes until someone chooses to end it. However, that's not the case. In war you're out to win and secure the safety of your country and its people. I cant judge the decision of my country's commander-in-chief and advisor(s)of the time as being correct or incorrect. There are some who say that the decision to drop the Atomic Bombs and the resulting soon to be end to the war ultimately saved many lives in comparison to the casualties that would have resulted from a long drawn out campaign in the Pacific. I cant say if this is factual or not. I honestly dont believe anyone can, without the ability to go back in time to explore the alternative. One thing is for sure, though. It would be correct to say it saved more "American Lives", as opposed to just saying more lives in general. That will appear to be a very selfish justification (mind you I'm not the one justifying it- I'm just repeating what has been said), but that's the mentality of War.