The British might have done genocide the most the good ol' fashioned way, but I really think at least in per-capita terms the US will be recognized in future history books as the worst. They mastered the art of genocide to the point that we don't even think of them as responsible for all the deaths they cause.

Do we MLs even call what happened in Iraq a genocide? I mean, millions of civilians died at the hands of the US. Not only places we directly invade but what about everywhere we strangle economically, where we install fascist dictators, at that point I feel like the death and destruction outweighs the Brits by a magnitude.

The British imperialists bowed out and chose to live in their "garden" peacefully while the Americans inherited their death machine and revolutionized it with Nazi inspiration. We modernized it and mastered the craft of being so purely evil and yet in such a way that most people wouldn't associate the US with genocide save perhaps that of the Native Americans (arguably another British genocide as well).