No, they're anti-war.
Not buying, sir.
"Un-American" is a term in this country that has been used to attempt to shut people up for many many moons. It was crap then and it's still crap.
You can disagree with their position. You can say that they're wrong, that they're unfair, that they're partisan. You can even call their patriotism into question, though that is a highly subjective suggestion. But you cannot, in fact, call someone who is exercising his free political speech "un-American", because what he is doing is quintessentially American.