I don't favor intervening in Syria, but I also don't favor US Presidents looking like a feckless amateur, which is precisely what Obama has done by whipsawing on his decision. Let's go to Charles Krauthammer:
“Look, I think he should go to Congress,” he continued. “I think it is absolutely necessary. But he has done no preparation. What they should have done — I mean, this is sort of amateur hour. When there were the first attacks six months ago or if you like, when we had the current attacks, he should have immediately have called in the Congress the way the prime minister of Britain had called in the parliament, had a debate and got a resolution and then went out and told the world we are going do x or we are not going to do x.”
And now let's got to Brit Nile Gardiner, who argues that "Barack Obama is proving an embarrassing amateur on the world stage compared to George W. Bush" (ouch, that'll sting):
George W. Bush was a conviction president on foreign policy matters, driven by a clear sense of the national interest. President Bush emphatically made his case to the American people and to the world, explaining why he believed the use of force was necessary, and dozens of countries decided to follow him. In the case of Barack Obama, whose foreign policy has been weak-kneed, confused and strategically incoherent, the president hasn’t effectively made the case for military intervention in Syria, and has made no serious effort to cultivate support both at home and abroad. President Bush may not have been greatly loved on the world stage, but he was respected by America’s allies, and feared by his enemies. In marked contrast, Obama hasn’t generated a lot of respect abroad, and he certainly isn’t feared.
The only thing Obama accomplished with his volte face was to make David Cameron look competent by comparison.