John Kerry's ad lib remark yesterday (it wasn't cleared with anyone) that Syria could avoid war if they turned over their chemical weapons to the international community presented a perfect opportunity for President Putin to get the upper hand in the Syria debate and probably forestall an attack.

Within hours of Kerry's mutterings, Putin had turned Kerry's off hand comment into a proposal to avoid war. Moscow said they would work with President Assad to make Kerry's "rhetorical arguments' as the State Department put it, into a concrete proposal to avoid war.

Yochi Dreazen of Foreign Policy asks "Did Kerry Just Ad-Lib His Way Out of a War"?

The Obama administration reacted much more cautiously, noting that Lavrov had provided no timetables or details about how his idea would work in practice, but White House officials didn't dismiss the Russian plan out of hand.

"We're going to take a hard look at this," Deputy National Security Advisor Tony Blinken told reporters at the White House. "We'll talk to the Russians about it."

By this evening, President Obama seemed receptive to the Russian proposal. In a series of interviews, he called it a "modestly positive development" and said he would hold off on a strike if Assad relinquished his chemical weapons.

The relatively warm U.S. response came in spite of the fact that the Russian proposal appeared to take the Obama administration by surprise. Lavrov spoke to Kerry by phone before his press conference in Moscow, but State Department spokeswoman Marie Harf said she didn't know whether Lavrov had given his American counterpart any advance notice that he was about to float the idea of putting Syria's chemical weapons under international control.

Still, it's far from clear how Lavrov's proposal would work in practice even if Assad signed on. Syria has dozens of chemical weapons facilities, many of them moveable, and the U.S. intelligence community would have a hard time knowing where more than a fraction of the sites were at any one time. That, in turn, would mean that Obama would have to effectively take Assad's word that he'd turned over all of his weapons -- an assurance the president would probably be unlikely to trust. The weapons themselves are difficult to handle, so physically moving and ultimately destroying them would be dangerous and time-consuming, adding another complication to the president's calculus.

Either way, the Russian proposal could give the White House a face-saving way to pull back from launching a military intervention into Syria that has almost no public or Congressional support. President Obama and his top aides have spent days arguing that failing to punish Assad for using chemical weapons against his own civilians would threaten U.S. national security by making American adversaries believe that they could develop and use weapons of mass destruction without repercussions. Obama himself will make the case for striking Syria in a television address Tuesday night. 

Of course, it may all just be a delaying tactic. Assad could "negotiate" endlessly, meanwhile fighting and continuing to win the civil war. The principle of "punishing" a chemical weapons user would go by the board, and the war criminals who launched the attack - whoever they were - would get off scott free.

And the Obama PR machine, aided by his allies in the press, would spin this humiliation of Russia saving Obama's face into portraying the president as the greatest statesman since Frederick the Great. Putin may even help with that notion, given that Russia would much prefer to keep their new found dominance in the Middle East something of a secret. Better to have the fool Obama propped up as a straw man while the real power wielded by Moscow remains hidden.

Can Obama really negotiate with Assad to give up his chemical weapons and then 6 months down the road, renew his call for an attack? Not likely. In that case, Putin and Assad would have triumphed and Obama left in the dust.