To paraphrase Community: "All this time, we thought the Germans were the Germans, but it turns out we're the Germans."
So background: both America and the Axis of WWII have committed genocides. America has actually committed two, but let's just focus on the one we're more "proud" of. And I use the term pride there intentionally, because I'm talking about slavery and the continued "pride" of certain segments of society in the Confederacy.
These two cases give us a very interesting contrast on how to respond to your country doing something really, really fucked up. The former Axis nations, for instance, have pretty much banned all things associated with the Nazi/Mussolini regimes, outside of historical education. For instance, there was a midfielder in Greece recently given a lifetime ban from the Greek futbol association for throwing up a Heil Hitler salute after scoring a goal.
This is a debatable punishment in its extent (though I for one have no problem with it), but it's at least a clear rejoinder to folks who express Nazi ideology. And that clear rejoinder is this: "Hey asshole, we tried that and it went really, really fucking wrong. Knock that shit off." It seems as if the former fascist genocidal nations have realized that genocide is something to be remorseful about. Seems simple enough.
Now contrast that with how America remembers one of our genocides (we just ignore/erase from history the other one). In plenty of places, school children are taught there was never really a genocide and that the South and North were fighting over how big the Federal government should be. We have plenty of people who still fly the flag of the genocidal regime under the aegis of "pride." Fuck, the state fucking capitol in South Carolina still flies the Confederate flag. What's the message here? Well, it sure looks like it's "Remorse? Fuck you, we ain't remorseful about genocide. in fact, we're fucking proud of it."
Now this is the point where a Confederate genocide defender will say the South was about much more than slavery, and while slavery was maybe regretful, there's still so much to celebrate.
Fuck you, if you're trying to make that argument.
Because let's apply that logic to Germany. Sure, the whole Holocaust thing was bad, but there was so much to celebrate in Nazi Germany. After all, it's not celebrating the Holocaust, it's merely taking pride in the past! That's why we still fly the flag of the Third Reich over the capitol building; it has nothing to do with racism and how dare you imply that!
Sound pretty horrible? Good, you've passed the test of being a human being. If you think it's unfair to compare the two cases, my condolences, for you've failed the test of being a human being.