The floodgates of Arab diplomatic restraint on Syria have finally been breached. In the past few days, both the Gulf Cooperation Council and Arab League issued their first official statements on the situation, expressing alarm at the Syrian government's excessive use of force and calling for an immediate end to violence. Even more important, the Gulf's most influential leader, Saudi Arabia's plainspoken King Abdullah, followed up with his own personal blast at the Assad regime, declaring that "What is happening in Syria is not acceptable to Saudi Arabia" and calling for a stop to "the killing machine." For good measure, the King recalled his ambassador from Damascus, a step immediately echoed by Kuwait and Bahrain. (Fellow GCC member, Qatar, actually closed its embassy last month).

True, none of the various statements called on Assad to step down. All urged the regime to implement meaningful reforms immediately. But don't be fooled. For the extraordinarily cautious Abdullah to move out against Assad so aggressively -- after almost five months of sitting idly on the sidelines -- is a sure sign that he's betting the Syrian tyrant's days are numbered.

The final straw for the Saudis appeared to be Assad's Ramadan Rampage, during which Syrian troops have laid waste to the cities of Hama and Deir az-Zour. Up to 300 civilians may have been slaughtered, making it by far the deadliest week of the five month old uprising, where the death toll now stands in excess of 2,000 souls. And no doubt most distressing of all for the Saudi monarch is the fact that the vast majority of the victims are fellow Sunnis.

Weeks ago, a senior Saudi official told me that, from the beginning of the Syrian upheaval, the King has believed that regime change would be highly beneficial to Saudi interests, particularly vis a vis the Iranian threat. "The King knows that other than the collapse of the Islamic Republic itself, nothing would weaken Iran more than losing Syria."

When pressed on why, then, the Saudis' response to the crisis had been so passive, my interlocutor essentially pinned the blame on uncertainty over U.S. policy. Risk-averse under the best of circumstances, the Saudis, he said, were especially loathe to take on the Iranian-Syrian axis on such an existential issue absent assurances of America's determination to see Assad gone. At least at that point in early July, the Saudis still claimed to "have no idea what outcome Obama really wants in Syria and what his strategy is to achieve it." 

Since then, the U.S. position against Assad has hardened considerably -- though (inexplicably) still stopping short of an outright call for him to step down. Whether that shift helped embolden the Saudis to speak out now is unclear. It's possible that Assad's Ramadan bloodlust, combined with a growing conviction that his regime is destined for history's dustbin, were sufficient to move the King to act.

Whatever the case, there's no doubt that the Saudi condemnation represents a major development, one that the Obama administration should move quickly to exploit. Abdullah's public vote of no confidence is a significant blow to Assad, an important morale boost for anti-regime forces, and an influential signal to the rest of the international community, particularly the Arab and Islamic worlds. Washington should be doing everything in its power to keep ratcheting up the pressure, producing a cascading series of shocks from the outside that -- together with the relentless internal challenge of the protesters -- seek to crack the regime as soon as possible, with the aim of short-circuiting the grinding, drawn-out escalation of brutality, death, and hatred that currently appears to be leading inexorably toward full-blown sectarian conflict and civil war.

Assuming that Syria's security services have no intention of allowing U.S. Ambassador Robert Ford to undertake a repeat performance of last month's remarkable sojourn to protect the people of Hama, Obama should follow the Saudi cue and officially recall him. Simultaneously, Assad's man on the Potomac, Imad Mustafa, should be expelled for conduct inconsistent with his diplomatic status -- including systematic efforts to surveil, intimidate, and threaten Syrian-Americans -- and his embassy shuttered. Key European allies should be pressed to follow suit.

Economically, aggressive sanctions against the Syrian oil sector should be fast-tracked -- in line with the nearly unanimous pleas of the Syrian opposition. As detailed in a valuable primer prepared by my colleagues at the Foundation for Defense of Democracies, sales to Europe (led by Germany, France, and Italy) of approximately 150,000 barrels of oil per day account for at least a quarter of the regime's total revenues -- and probably more in light of the drastic deterioration in the overall economy since the uprising began. Deprived of those revenues, Assad's ability to subsidize the key constituencies that keep his killing machine intact will be dramatically constrained.

Moreover, Holland's Royal Dutch Shell and, to a lesser extent, France's Total, are important players inside Syria's energy sector, providing critical technology and investment to sustain production. Working closely with Saudi Arabia, the world's largest oil producer, Washington should be able to craft a set of incentives and work-arounds that ease the burden felt by our European allies, and mitigate the relatively small loss of Syrian oil to the global market.  

Perhaps most importantly, U.S. leadership is desperately needed to bring together the impressive, but so far disparate coalition of major countries now clearly inclined, however reluctantly, to see Assad's removal as the sine qua non for resolving the increasingly dangerous Syrian crisis. A comprehensive strategy is required to topple his dictatorship as quickly as possible, and shepherd as peaceful and orderly a transition as can be fashioned to a more decent, accountable government. It requires a genuine unity of effort that fully mobilizes, synchronizes, and focuses the substantial diplomatic, economic and intelligence capabilities that can be brought to bear on the Syrian situation by the likes of the United States, Turkey, France, Germany, Saudi Arabia, Qatar, the UAE, and the rest of the EU. 

King Abdullah's dramatic intervention has created a potential turning point in the unfolding Syrian tragedy, but one that can only be fully taken advantage of by authoritative U.S. leadership that infuses our allies with confidence and a clear sense of direction, and our adversaries with the inevitability of their own eventual demise. The Obama administration has been handed an important opportunity to secure U.S. interests. The president should act quickly to seize it.