From what I see many US citizens actually believe the narrative. Perhaps not so much in Europe, but the "war on terror" story has been going on for years in the US. People who haven't been out of the country cannot understand why this could not be the case. All they know is that there are some pretty fanatic people in the Middle East, who fly on buildings and drop chemical bombs. People who live in smaller countries with more neighbours and especially closer to problematic areas are more likely to understand that it's never that simple.