I actually asked what made me a wingnut, but now that you've called me a troll as well, i'll respond to both:
It is not being troll to comment on a signature that is clearly a provocative political response to the recent election (he's confirmed as much), especially a signature that calls people he seems to disagree with "common idiots." Using that signature while calling the left "wingnuts" and pre-emptively attacking anything they might post as "fucking nonsense" IS in fact acting like a troll.
It is not being a wingnut to point out to someone that he discredits his argument by indulging in stereotypes and making intentionally insulting generalizations about those who might disagree with him.
His stereotype of all Islamic groups as not being "moral enough" to follow the Geneva Conventions is wrong. Many Islamic groups adhere quite strictly to a moral code, and, in fact, many of the Islamic militants fighting in Iraq are acting on the conviction that our culture and our invasion of Iraq go against that code. You might not agree with them, but they are certainly "moral enough" to follow an agreement and adhere to a code of behavior.
His generalization that the left needs to do "homework" because they lack an understanding of the Geneva Conventions has no basis. Many people on the left have studied the Geneva Conventions quite thoroughly.
As for "attacking a perfectly valid statement without proof to the contrary": He offered no proof of the statements I've commented on in the first place, and so I do not see how you can call them valid. Those statements are faulty generalizations on which he seems to have built at least part of his argument. I actually called most of his argument reasonable, but pointed out that his provocative style and faulty generalizations undercut it.