The Single Worst Thing Obama Did in Syria?

I would say his failure to respond adequately in Syria is the single worst thing that Obama did. But if I'm tracing it back, which American I blame most for Syria, it's still going to be George W. Bush and Dick Cheney. He really didn't step up because he was thinking it out, like thinking of all the ways it could go wrong and what would happen. How do you even like reconcile any of that? It's like, wow.