re: clearly a biased list
Might be interesting to take the whole rest of the world and extend their records back to 1600 and see how many nations come out smelling like roses in the genocide department. I notice that only America's record goes back that far.
An interesting reference on this kind of thing can be found here.
I dare say America, including our military and our technology, has saved a hell of a lot more lives than it has taken throughout history.