Cynicism aside, realism informs us that this cycle of pain has been repeated throughout human history, again and again. War becomes attractive, and is viewed as an acceptable alternative to negotiation, once enough people have forgotten what it really means, and with attention spans ever shorter amid the most readily available surplus of useful information in mankind's history, it's hard to come up with a plausible argument for the maintenance of peace.
I might suggest there are effective uses to thoughtful knowledge of the past, but that's thinking, and I'm not sure this notion is of interest at the precise moment when American wheels threaten to skip rails.
I'd suggest that recalling the lessons of the Holocaust, and remembering why we return so often to Eichmann, Arendt and the "banality" of evil, except that so many of our homegrown fascists are yelling so loudly, and the sound of those boots landing on human faces tends to drown out the teaching moment.
Why Adolf Eichmann’s final message remains so profoundly unsettling, by Giles Fraser (The Guardian)
... All of which doesn’t make Eichmann any less disturbing. It makes him more so. For what Arendt’s Eichmann did was to demonstrate that ordinariness is no protection against doing great evil. Cesarani too, sees Eichmann as a sort of “everyman”. No, he wasn’t just a travel agent, indifferent to the destination of his passengers. He was personally responsible, a responsibility he blindly denied right to the end. Which is precisely why the moral message of his story remains profoundly unsettling: if ordinary people were capable of such great evil, then, given the right circumstances, so are the rest of us.