I'd be interested in hearing what you disagree with Chomsky .. in my opinion he is one of the most enlightened American academics we have right now, and I personally wish more Americans were exposed to his point of view - it would certainly calm a lot of fires if the average American realized the true, human, cost of their empire.
As far as calling Americans terrorists- how else would you describe the 80+ military actions that America has taken, in the name of its people, since the end of WW2? I mean, policing the world is one thing; bombing certain cultures to absolute oblivion is another thing entirely. What could it be rather than the mass export of terror to the non-militarized world, when American drones act with impunity, American agents operate undeterred in foreign governments, and so on? I think that anyone 'disagreeing' that America engages in terrorism clearly needs to take another renewed look at the situation .. America is most definitely one of the most terrible nations on the planet, in terms of its value of human life. I say this with sincerity, and I do truly believe that America has a lot of positives; however, they are far, far outweighed by the negative impact on humanity that the American people have, and continue to have daily, on the world at large. Every single drone strike is a crime.