There is one rebel group in Syria that is 100% reliable, the Kurds! They are fighting ISIS to a standstill with nothing but small arms and guts. With a little help they could really regain some ground. However, right now they are on a US State Department list of terrorist organizations because of their guerrilla war of independence against Turkey. At a minimum we should take all the Kurdish groups off the terrorist lists. While the Turks would be very unhappy with the US if we armed the Syrian Kurds, I don't think we have any reason to care about hurting their feelings. They won't let us use our own airbase at Incerlik to fight ISIS. If we promise the Kurds they can keep what they take, they might be willing to fight further away from their traditional turf. Longer term, I think a lot of people in the ethnic stew of the Middle East might actually like to be under Kurdish administration. They certainly do a better job in their provinces in Iraq than most of the other countries in the area. By Middle Eastern standards, they are religiously tolerant, democratic, pro-American and even pro-Israeli. The only drawback is that arming the Kurds could lead to an independent Kurdistan. The Kurds got screwed when the post World War I borders were drawn. There are 40 million Kurds, but no Kurdistan. Kurdish independence would require redrawing the sacred boundaries. Since we obviously don't care about the territorial integrity of the Ukraine, why should we care about the territorial integrity of Syria and Iraq?