You could see it in Obama's face. The relief. He almost broke into a smile in one of his six television interviews as he confirmed that military strikes against Syria are off, for now. And he is off the hook.
It's just as well. It wasn't just his credibility that was on the line. It was his presidency. And the credibility of the United States.
After a year of diplomatic deadlock on Syria, more happened in a rollercoaster 24 hours than anyone thought possible.
It started with an accidental peace plan. At the end of a tough week arguing for military action, John Kerry answered a routine question about Assad with what sounded like a proposal, attached to a deadline.
Assad, he said, could avoid military strikes by handing over his entire stock of chemical weapons within a week. "But he won't do that", Kerry said.
In Moscow the remark was seized on by his Russian opposite number, who called it a plan. "It wasn't!" Kerry later told him on the phone. Too late. The ball was rolling.
The Syrian foreign minister immediately said he welcomed it, in spite of the fact that Syria still doesn't admit to having any chemical weapons.
In London, David Cameron was in the Commons, improvising a response to a plan that was gaining momentum by the minute. Like Kerry, he was sceptical but if the proposal was serious, it deserved a look.
At the White House they saw a way back from the cliff. The vote in Congress was not looking good. In fact it was a disaster.
The House of Representatives looked like it would reject military strikes by four to one, maybe more. The Senate was better but not by much. The American public was lining up against military action. The Russian plan was a face saver. And a life saver.
But was this all so accidental? Or was this cake pre-cooked?
Russia and the US have been worried about Syria's chemical stocks for two years. Even more so since Islamists began closing in on bases in Homs and elsewhere, where the poisons are stored.
They've been discussing how to secure or destroy them for months. The Syrians too have been involved in these talks. They too saw the dangers.
Kerry's seemingly off the cuff remark was born of months of talks about how to get agreement.
So now suddenly, the debate has shifted. The vote in Congress is off. Military strikes are off. All eyes are on Damascus, the UN and Russia:
Will Assad agree to do this?
Will UN Inspectors take control of chemical stocks?
Will the UN pass a resolution authorising action if the stocks are not destroyed?
When will the stocks be handed over?
How will they be destroyed in the middle of a war, where and when?
The devil is in the detail. And this will takes months to resolve. After which everyone will have forgotten how this came about.
Suddenly, no one is talking about the poison gas massacre that killed hundreds. No one produced evidence against Assad's army publicly and now everyone is content to leave that massacre to one side.
The UN Inspectors will soon report that it WAS a chemical attack, but it won't lay blame. Everyone can step back from the brink and everyone wins from the new plan.
Except the rebels, who wanted to add cruise missiles to their arsenal against Assad.
And most of all, the victims. They lost their lives. Now they will lose justice. Their deaths go unanswered. Their mass murder forgotten as the world heaves a sigh of relief.
In Damascus this morning, the explosions ring out across the city. President Assad's army is pounding the rebel held suburbs with conventional weapons. That's all right then. Those weapons, used by both sides, have killed a hundred thousand people so far.
How many more will they kill before everyone stops smiling, agrees on the Russian plan and destroys those really nasty weapons?