The government of Syria will collapse. The Middle East needs a haven for Christians and those of the various minority brands of Islam. Nation states in the region have been largely unstable. An example of economic as well as religious freedom can only help.
I therefore suggest that a Coalition of the Caring establish an International Peace Zone on territory currently assigned to Syria, based around the port city of Latakia. (This would not be a resurrection of the Alawite State, although this last shows how the political groupings of this part of the world have been in continual flux for the last few thousand years.)
The International Peace Zone would not be a sovereign state - who needs more of those? - but a semi-autonomous creation somewhat along the lines of the Shanghai International Settlement. It would also be a free port, with an aggressively free-trade policy along the lines of pre-handover Hong Kong. The United Nations would not be involved.
Security would be provided by garrison troops provided by the members of the Coalition of the Caring. Given the state of the region, vigorous policing would be required. Internal democracy is not a goal of the International Peace Zone.
This area of the world has much going for it, with the major exception being the local political arrangements which are, almost unbelievably, getting worse. Here is an opportunity to change that, in a small but potentially profound way.
What would you want to see in an 'International Peace Zone'? (Yes, the name is chosen to appeal to its natural enemies.)