Stephen Sestanovich offers up a remarkably bad defense of the importance of “credibility”:

A great power values credibility so opponents know not to challenge its interests. That’s why Susan Rice, his own national-security adviser, said the damage done by backtracking on the “red line” would be severe.

Has it been? Obama says no, but surely he understands that if he had taken out Syrian President Bashar al-Assad’s air force in 2013, as many were urging him to do (and as he clearly could have done), Vladimir Putin would never have intervened in Syria in 2015. Obama may not ask himself why Putin would have held back, but the answer is very clear. He would have worried about taking on the United States. Now he doesn’t. Putin has taught us that credibility means something.

This isn’t the usual argument that “credibility” fans make about Syria, but this one doesn’t make any sense, either. Russia intervened in Syria when it did because the Syrian government was losing and Moscow wanted to shore up the regime because it considered the regime’s survival important enough to take that risk. How would attacking and weakening the regime in 2013 have prevented a later Russian intervention? Attacking a Russian client then would probably have made Moscow want to increase its support for Assad earlier than it did. “Credibility” advocates think that U.S. intervention in Syria would have intimidated Russia, but there is good reason to think that it would have provoked them instead. Just because Russian intervention in Syria took place after the decision not to bomb the Syrian regime, that doesn’t mean that it happened as a consequence of that decision. The “credibility” argument is typically little more than the post hoc ergo propter hoc fallacy combined with tendentious advocacy for aggressive policies. As Shibley Telhami put it earlier this week:

The “credibility” argument isn’t credible. Sestanovich doesn’t talk about the claims that Syria hawks made during the 2013 debate, but it’s worth recalling them to understand that the things they said would happen did not happen. Syria hawks warned that U.S. allies would lose confidence in American security commitments if the U.S. didn’t attack Syria. This never made sense. Threatening to attack another government and pledging to defend against someone else’s attack are two very different kinds of commitments. Regardless, the U.S. decision not to bomb Syria didn’t undermine any of our treaty commitments. Some administration officials warned at the time that adversaries would interpret the decision not to bomb as an invitation to aggressive behavior. On the whole, thee was no new aggressive behavior, and as we saw last week with the Ioffe report on Syria and Ukraine the U.S. decision not to bomb Syria had nothing to do with later Russian actions regarding Ukraine. There is no evidence that “credibility” matters in the way that hawks routinely claim that it does. There is a fair amount of evidence that it doesn’t work that way at all. Hawks insisted that disasters would follow a loss of U.S. “credibility” in Syria and have been proven wrong.