This film represents a huge leap forward from the sickly, prescriptive preaching of "the world would be lovely if it wasn't for the bad people" into an aknowledgement that there are fallible human beings on both sides of the racial divide, some of whom mistake personal bitterness for a moral justification of hatred. Hearteningly, the more recent "Crash" also takes this approach, though from a wider perspective than American History X's specific focus on racially motivated violence.
I take the point of the previous reviewer that this film reduces some of the neo-nazis to cardboard cut-outs, but to be fair its approach was ambitious enough already. (To fully develop all the characters in such a complex subject might require a stage tragedy rather than a general release movie.) Similarly, the handful of liberals were probably necessary, sadly, to prevent idiots taking the film as a vindication of their so-called beliefs, and also to avoid alienating much of the target audience. For a film released in 1999 this was a very brave production.