The darkest what??

In Washington D.C. a guided tour took us to see the Lincoln Memorial, and the Korean War and Vietnam War memorials that are very close to it. In the short stretch between the two war memorials there are a few stalls selling not exactly souvenirs, but badges and replicas and posters ad such, either military, "patriotic", or xenophobic. I was shocked, not culture-shocked but raged-shocked, when I saw that poster there. The photos are not very clear; they are the Twin Towers.

I would have thought that the genocide of Native Americans was the darkest page of American History. No, maybe slavery was. No, maybe the Civil War was (the guide told us that more people died in that war that in all the others put together). Even maybe, the Vietnam War was (sixteen years of war, were they crazy or what?), considering what a wreck they did of the place.

Oh, no. The darkest page in American History is not Americans being senselessly cruel to other people or to each other. It is other people being cruel to them. I see.