Obama has found his out, and a way to save face.
It won’t be HIM that backed down, but Congress.
Congress will vote NOT to allow him to use force, then Obama can say “I tried! But those meany obstructionist REPUBLICANS would rather children be gassed to death!!”
And his sycophants in the US Media will gladly parrot this line over and over.
They can say what they like, but the fact is Obama’s foreign policy would have been exposed as a fraud.