There is an informal rule that former presidents don't comment the acts of their successors.
And now we have here Bill Clinton. He is not only criticizing Obama's Syria policy. He is also suggesting that Obama's only reason for his policies are the opinion polls and suggesting that that makes him into a "complete fool".
His only excuse is that it happened in a closed meeting. But Clinton hasn't apologized and instead continued his statement in the full public eye. Never mind that Obama is a fellow democrat.
It certainly doesn't enhance the credibility of Clinton's wife as presidential candidate. And as for Obama, it doesn't enhance his credibility that he takes action because Clinton called him a "fool" and a "wuzz".