When Assad had almost wiped out the opposition with support from Lebanese Hezbollah, he apparently wanted to reward Hezbollah and Hezbollah was launching attacks on Israel from Syria. Israel doesn't want that. The Al Qaeda "rebels" want to ultimately attack Israel, but right now Israel seems more concerned with not getting attacked by Hezbollah.
80-90% of Muslims are Sunni. The U.S. and Israel is taking the side of the 80-90% of Muslims who are Sunni against the 10-20% who are Shia by having so far supported an overthrow of Assad that the U.S. claims not to be supporting now.
Iran is at least predominantly Shia.
Saudis are predominantly Sunnis.
The Sunnis and Shia have been killing each other for a long time.
All this said, I agree with you that it makes no sense.
Could it be simply the common enemies of all involved (obama and moslems) are the Jewish Peoples and Christian Peoples?
Could it be that simple?