“What happened in Egypt was the minimum response to the movie,” said Abdelrahman Said Kamel, 30, who was selling brightly colored women’s clothing at a street kiosk Saturday and said he had protested at the U.S. Embassy several times this week. “I can’t understand how America is trying to help us economically but insulting our prophet.”
Note the metonymic phrasing: America is insulting the prophet; the actions of an isolated crank are taken as representative of the whole country. Later in the same article another Egyptian is quoted as saying that the U.S. never helped Egypt; rather it helped the Mubarak regime keep Egyptians oppressed and unemployed. These views are widespread enough to make a spark like the video an effective catalyst of protest.
Dan Nexon notes that the video acted as a trigger because it fit "a particular pre-existing script concerning identity relations: 'Americans/Westerners hate/disrespect Islam/Muslims.'" I would only add that this script has existed for a long time and has proved very durable: statements by U.S. presidents and officials repeatedly distinguishing between Islam on the one hand and extremist violence on the other have not apparently had much effect in diminishing the script's force. Scripts about identity relations presumably can take on lives of their own and become almost impervious to alteration, but the remarkable durability of this script must lie in, among other things, deep-rooted historical and ideological sources, which are kept fresh, so to speak, by some aspects of U.S. foreign policy. (I am leaving this deliberately vague; people can fill in the blanks in their own ways.)
A final note on U.S. embassies: The attack on the compound in Benghazi may have led some people to think that U.S. embassies (as opposed to consulates, etc.) are not well protected. My impression is that this is not true. U.S. embassies in many parts of the world, I suspect, resemble rather forbidding fortresses (certainly that was the case in Bangladesh when I was there a number of years ago) and routinely have armed guards. That doesn't mean they can't be stormed by determined protestors, but people whose image of an embassy is a nice little townhouse in a leafy portion of northwest Washington, D.C. should know that U.S. embassies in many parts of the world are not like that at all.
Update: Fouad Ajami has a WaPo op-ed on this. I'm not a big fan of his but at least parts of this piece are ok. He downplays the role of U.S. policy, however.