I mean you can blame the US for many things, but if you want to blame large groups of people and institution in this case the US is not to blame. He had a fatwa

I mean you can blame the US for many things, but if you want to blame large groups of people and institution in this case the US is not to blame. He had a fatwa over his head for 25 years. And Islamic people don't take insults of their prophet lightly, not even moderate ones. However there is only a subset, mostly young man, really willing to use violence over it.