User blog comment:Longdead97/Ulfric's war effort & gaining support. Smart move or no?/@comment-1840877-20130327090400

Well, neither the Stormcloaks nor the Forsworn are very chummy with the Imperials, so theoretically, they could form a temporary alliance based off the whole "enemy of my enemy" thing. However, I can't see that happening in practice, because of the Markarth Incident. Madanach would probably respond by sending the Stormcloak delegate's head back to Windhelm, along with a note saying, "Dear Jarl Ulfric. Screw you. Love, Madanach." In short, it ain't gonna happen.