Edited to replace original incorrect Herzog attribution with my own version that correctly attributes the quote
While it's no doubt a cool quote, it's also kind of condescending. Somehow, a horrific moment in history has turned into an arrogant warning. And even at that, it's a warning to a country that Germany modeled upon for its concentration camps. It reads like, "Don't do what you've already done (that we copied), you dumbasses." I don't disagree with the implied dumbasses vibe, but the naive arrogance takes away a lot of momentum of this quote for me. That is to say, the U. S. has already messed up on a massive level before, to the point that Germany borrowed from them to do the terrible things that Germany did, yet this reality has seemingly been forgotten. Why did he forget this? Were those exterminated in the U.S. not important enough to be remembered in his view of history? In other words, the plight of millions of indigenous, enslaved people of color, and many others aren't even accounted for here. The warning has eliminated them from history.
It's a sideways glance at the quote, but now I can't stop reading it from that angle.