From The Weekly Standard, a cogent article on Anti-Americanism by Andrew Thomson, a former government minister under John Howard in Australia:
I think Thomson puts the date of the first manifestation as way too late.
I think there is a seamless line from the anti-Pershing missile campaigns of the 1980s, most of which were being prodded and funded by the old KGB and Stasi, through the anti-globalization riots and demonstrations of the 90s to the Islamist attacks.
Generally, it follows a similar pattern of grievance and the embodiment of the grievance in one symbolic monster: the United States. The grievance may be rooted in realities of poverty, but that hardly matters. It's more important that the grievance be seen as a chance to slap at the US.
It's like that old Abbott and Costello routine where Abbott gets the big guy angry at Costello by slapping him and saying that is what Costello wants to do.
My new slogan, swiped and modified from a skateboarder's t-shirt:
You say Unilateral Hegemon like it's a bad thing.