I remember the atmosphere post 9/11. I'm not even American and I was still in highschool when it happened but we were so hyped by the constant propaganda (almost nothing else was being talked about on TV for a few weeks) that I and quite a few guys my age I knew were ready to go to war to fight the "terrorists".
By the time the Empire invaded Iraq, the sentiment had shifted so much that being anti-American became part of our shared European identity 😛