What you are or think you are sure of and what I am or think I am sure of in that part of the world amounts to nothing. There is no way our involvement in Syria would improve anything for us because we cannot predict the outcome, nor is there evidence of any hunger for anything resembling a democratically run state. Freedom, to them, is apostasy. That the government considers itself Ba’athist did not stop them from aligning with coalition forces against Saddam Hussein in the Gulf War I. No matter what conditions we would seek to impose, the proposition for us is to enforce it by force, and see it deteriorate to default Al Queda control as soon as we leave or draw down forces. Our forces over there are or would be just a magnet for resistance. Should Assad lose power, that would just accelerate things towards AQ or other Islamist control.
If we are primarily concerned with the proliferation of chemical weapons stockpiled by Syria, the Israelis are 50 times better on top of that situation than we will ever be, and our intelligence (particularly under 0bama) has proven it is as likely to turn against Israel as towards any given Arab state. Thus, Israel is probably reluctant to share same with us. Very understandably. I’d like to keep it that way, consider present circumstances. We don’t get Arab logic, they don’t get ours. What we do in the name of imposing or allowing “freedom” is what they hate. It runs counter to their religion. I’m perfectly happy to let Israel take of whatever business they see as pressing and allow Muslims to wipe out other Muslims to their heart’s content. It’s a human tragedy but one that we cannot control and certainly cannot benefit from policing.
But as I said, a full-scale takeoever of Syria by Iran is a possibility and in that case we are talking about a national defense reason for involvement.
Sure, if you believe that Israel is Iran's only enemy you can try to leave the situation to them. However, it is naive to think that Iran won't continue to use their influence against us. And, if so,pre-emptive action on our part would be desirable, both to support Israel as the only democracy in the area and for our own interest and self-defense.