'After toppling Assad, how can the Gulf states control Syria besides the inevitable schism between Damascus & Tehran?'

"...Several leaders of the Syrian branches of the tribes continue regular visits to the Gulf states and often meet members of the royal families. A significant number have returned to the Gulf and become naturalised citizens mainly in Saudi Arabia, Qatar, Bahrain and Kuwait. Many hold privileged positions in these countries and, as the bloody crackdown in Syria continues, tribal kinships have grown closer, with tribes in Deraa contacting their "cousins" in the Gulf asking for a firm diplomatic and economic position regarding Damascus... ....

Another possible trend that favours Gulf influence in Syria is the growing prominence of Salafism (as opposed to the Muslim Brotherhood, which has strong links to Turkey). Salafism is increasing especially in tribal areas, partly because of the return of Syrians who have worked in the Gulf.

How the Gulf states will use these levers of influence remains to be seen, however. "Saudi Arabia has a limited understanding of the nature and diversity of the Syrian opposition," said Emile Hokayem, a Middle East analyst at the International Institute for Strategic Studies, "and risks espousing too closely the perspective of its tribal and Wahhabi interlocutors." Riyadh risks overreliance on the tribes, which remain largely divided.

But if these links are harnessed, the Gulf states' influence will extend from the north of Syria to western Iraq and Jordan, creating a "tribal crescent" in place of Iran's "Shia crescent" that today extends from Iran to Iraq, Syria and Lebanon."