Leon Panetta likes clichés. In a USA Today interview on Monday to promote his new memoir, the former defense secretary called on President Obama to “roll up his sleeves” and “step up to the plate” when it comes to solving the nation’s problems.

Panetta’s policy advice was pretty clichéd too. Like numerous other politicians and ex-government officials, he slammed the president for reneging on his threat to attack Bashar al-Assad for using chemical weapons. “When the president as commander in chief says that there’s a line out there,” Panetta declared, “At that point the credibility of the United States is on the line and so when they actually go ahead and use chemical weapons, then I think it’s important for the president as commander in chief to say a red line has been crossed and we’re going to take action as a result of that.”

So far, so familiar. What makes Panetta’s comments noteworthy is their timing. More than a year has passed since Obama’s Syria flip-flop and quite a bit has changed. It’s now widely accepted in Washington that America’s biggest problem in Syria is not Assad but ISIS, a threat Panetta says will require a “30-year war.” The U.S. still refuses to ally with Assad, but it is taking actions—like bombing ISIS targets in Syria—that strengthen his regime, at least in the short term.

Which raises an interesting question: In retrospect, does Panetta really believe the U.S. should have gone to war against Assad just months before turning around and going to war against ISIS? The claim that bombing Syria in retaliation for Assad’s chemical-weapons use would improve conditions on the ground was dubious from the start. Given that the U.S. is now fighting a war in Syria against ISIS, it is even more dubious today.

But like most other Obama critics, Panetta’s argument for why the U.S. should have bombed Assad has little to do with conditions on the ground in Syria. It’s all about American credibility. As Panetta told USA Today, “There’s [now] a little question mark [among America’s allies] as to, is the United States going to stick this out? Is the United States going to be there when we need them?”

The credibility argument was always a stretch. As I noted in a column earlier this year, there is a wealth of academic literature proving Panetta wrong. As Dartmouth’s Daryl Press writes in his book, Calculating Credibility, “A country’s credibility, at least during crises, is driven not by its past behavior but rather by its power and interests. If a country makes threats that it has the power to carry out—and an interest in doing so—those threats will be believed even if the country has bluffed in the past.”

But a few months ago, there was no way to prove Press’s contention in this particular case. Now there is. Since he declared war on ISIS, the Obama administration has been recruiting other countries to join the United States. And whatever you think of the war itself, that diplomatic effort has been remarkably successful. Ten different Arab countries have agreed to participate in the anti-ISIS campaign. Even John McCain and Lindsey Graham have praised the administration’s coalition-building skills.

All this illustrates the silliness of Panetta’s claim. It was one thing to speculate a few months ago that Obama’s chemical-weapons about-face would make it harder for the U.S. to convince allies to join a military coalition the next time. But the next time is now here. Roughly a year after supposedly squandering America’s credibility by standing down on chemical weapons, Obama has mustered enough credibility to convince a bevy of Arab countries to help us bomb fellow Arab Muslims in the heart of the Middle East. Which just underscores Press’s point: When predicting how other governments will behave in a given situation, governments examine the particular circumstances of that situation, not “credibility” per se.

In the coming days, dozens of journalists will interview Panetta for his book. In those interviews, he’ll likely attack Obama for undermining America’s credibility dozens of times. If even one journalist asks him for evidence to back up his claim, I’ll be pleasantly surprised.