Earlier quoted context omitted.
The moral compass that led us to slavery, the genocide of the Native Americans, and Japanese internment camps? The idea that the USA was formerly moral but has given it up lately isn't really supported by history.
And being the only nation on the planet to ever use nuclear weapons in anger. On civilian populations. Twice. When one talks about things that happened outside of the lifetime of one's audience, the response tends to just be "oh but that was a long time ago", hence the observations on recent trends.
But I suppose the better option was to conduct a land invasion of Japan which would have likely led to much more death and destruction. It seems the people of Germany had a positive note to consider while they were sifting through the rubble of their cities after the extensive carpet bombings the Allies conducted when they invaded their country; at least they weren't bombed with nuclear weapons.
It just bothers me when someone mentions that the US is the only country to use nuclear weapons on a civilian population in anger but not offer any sort of context as to why they did such a thing. Without context you are heavily implying that the US government just randomly decided to nuke civilians just for kicks. Which is quite sad since you are essentially doing the very thing you complain about in your second sentence, willfully forgetting your history.