Ahead of his speech tonight, the Washington Post reports that President Obama “does not believe he needs formal congressional approval” to use airstrikes in Syria.

Today, a number of commentators, from both the left and right, seem to be making versions of the argument David Frum—a guy who knows a thing or two about convincing the American public that bombing the Middle East is a good idea—puts forth here:

It seems like only last year that this president was asking Congress for authority to bomb Assad. Twelve months later, he will bomb Assad’s enemies. Why does bombing one side of a war require congressional permission, while bombing the other side does not? The administration doesn’t answer, because nobody is asking. Something must be done! This is something! Let’s do this!

There are good reasons to be wary about U.S. intervention in Syria, and I suppose it’s fair to bring up the president’s inconsistency here. But when you look at historical precedent, there’s nothing all that surprising going on here, and the difference between these two situations—bombing Assad and bombing Assad’s enemies—isn’t all that mysterious.

We know, from past example, that this president—and Bill Clinton and Ronald Reagan before him—is not opposed to taking military action without congressional authorization. In addition to the numerous covert actions taken against terrorist groups under the increasingly flimsy authorization of 9/11-era legistlation, the administration argued in the face of criticism from Republicans as well as liberal Democrats that no approval was necessary for a months-long military campaign against Muammar al-Qaddafi’s government in Libya.

In September 2013, when the administration briefly considered military action against Bashar al-Assad’s government following a massive chemical weapons attack, the decision to go to Congress was a break in precedent and treated at the time as something of a novelty.

Obama went to Congress in part because public opinion was overwhelmingly against bombing Syria. But as I wrote at the time, it doesn’t seem like the political fallout from a brief punitive bombing campaign would have been all that great if Obama had just gone ahead and ordered it.

By going to Congress, the administration suggested that it never wanted to carry out the strikes, but felt pressured to act to preserve U.S. credibility due to the “red line” over chemical weapons that Obama had set months earlier. Putting the decision in the hands of Congress gave the White House an out and the problem eventually went away—for the president and his advisors, not for Syrian civilians—thanks to a surprise Russian-negotiated deal under which Assad turned over his chemical weapons.  

Things are very different this time around. ISIS’s rapid expansion combined with the disturbing videos of beheaded American journalists have had an impact on American public opinion. Those factors, too, seem to have changed the president’s assessment of the threat posed by the group. Recall that back in January, Obama dismissed concerns over a (then) al-Qaida-linked group taking over Iraqi cities with the analogy, “if a jayvee team puts on Lakers uniforms that doesn’t make them Kobe Bryant.”

It’s certainly valid to argue that just because ISIS have proven themselves to be more Kobe than jayvee, it doesn’t mean that airstrikes in Syria are a prudent policy. And there’s a good debate to be had about the role of Congress in authorizing military action in an age of asymmetrical threats and drone warfare. But let’s not kid ourselves: Shooting first and asking Congress later has become the rule, not the exception.