Actually, the time to intervene in Syria is going to be when the fighting ceases. I think by now it is fairly sure that in the long run the Alewis will win, probably yielding some eastern territory to the Kurds - it does not matter to them, there are no Alewis or other minorities there, and the area is far from the Syrian heartland and divided from it by scrub and desert. It is when the Jihadis are finally defeated that the "international community" will be in a position to give orders to the Alewi government, that will need massive investment, and foreign organizational help in resettling those of the refugees who will be willing to come back. But you can't hope to blackmail a military minority while it is fighting for its life.