As the US military campaign ramps up in Iraq against the Islamic State (IS), many important questions remain unanswered in regard to the operation's imminent counterpart in Syria. It seems clear that US policy in Syria will involve some sort of force on the ground to complement the airstrikes targeting IS positions, heavy weaponry and troops. The Americans have guessed correctly that IS cannot be defeated unless taken out in Syria as well, and airstrikes alone are not enough to do that.
IS has already withdrawn from prominent buildings it took as headquarters in towns and cities such as Raqqa, instead adopting a lower profile and hiding among the locals and abandoning heavy armor for more mobility and stealth via lighter cars and vehicles. The million-dollar question is: Who will take on the role of the peshmerga and the Iraqi army in Syria?