I can agree that the film MUST be offensive, because as I can see, many of you are offended. Reprehensible? I should hope not. People shouldn't feel guilty about creating something because it might offend someone. People like Mary Whitehouse are always on hand to tell us (grown adults) what we can and cannot watch, based on HER own personal morality system. Well screw that.
I also live in Northern Ireland, so yes, I do know terrorism first hand. My own father was in Derry on Bloody Sunday when the British troops opened fire on the peaceful civil rights marchers.
I can understand why you are offended by it. The United States seems to have had an unfair share of political assassinations. I know, as you can tell by my avatar, but just don't take it personally. If the US made a film about a princess being killed in a car crash, I'm sure there would be people upset over here too. But I can only defend my own opinion and I have been.