At some stage Americans will look back and realise that those guys who flew in to the towers destroyed more than anyone could possibly have imagined at the time, and they're still destroying the basis of American society every day. British too. I'm sure they had no idea that that one act would have led to the complete destruction of the rules of civilisation we've built up over so many years, leading to spying, arrest without charge, unlimited times of detention, torture, the complete alienation of the Muslim world, massive national debt, paranoia, etc.