I think so too. Especially after I found out he was seventeen when he enlisted and had to get his parents' permission to sign up. So he had to portray himself as very gung-ho at one point, yes?
I don't think anyone can be brainwashed that quickly, so he had to have had some involvement with these peacenik clowns beforehand. Maybe a teacher at his high school. I think he enlisted for the sole purpose of deserting later as a political statement.