Don’t you think there was an agreement to let the terrorists kill the Americans at Benghazi?
No. I think there was an agreement to let our ambassador be kidnapped so The Won would have an excuse to trade/release the blind sheik.
When a couple SEALS showed up and offed a bunch of the miscreants, the rest assumed they'd been betrayed (it is what they would have done, after all!) they got po'd and emasculated, sodomized, killed, and sodomized Ambassador Stevens out of pure spite and revenge.