It seems that if they are fighting within the Islamic community itself, it's more a case of interpretation, than a religious war . I would think, that if it were truly a religious war, then it would encompass all Muslims...not some individuals that disagree amongst themselves.
Try taking a look at the fighting in Africa. Who are the aggressors? Who are the aggessors in Chechnya? In Malaysia? In Thailand? In the Phillipines?
Since the goal and objective of the islamists (i.e., radical mohammedans who believe in holy war) is to spread islam and make it the dominant movement on the planet (and virtually all of the islamists are in lock step with that) the conflict they have started is definitely a religious war. If Catholics started a conflict to spread Catholicism worldwide via terror and violence, and their main target were Buddhists, and the Protestants were opposed to the conflict, but said and did nothing, that conflict would still be a religious war, wouldn't it?