Speaking to the Bloomberg Law podcast on March, 12, 2026, UCLA Burkle Center Director Kal Raustiala said, “It’s correct that Congress is empowered to declare war under the Constitution, but Congress has only done so five times in American history, and we've used force ... over 200 times. So it’s pretty well established that there's lots of uses of force that the president can engage in without a declaration of war. And in fact, in the post–UN Charter world, a declaration of war doesn’t even really make sense. The system is predicated on the idea of self-defense as the main rationale for the use of force.
“But in any event, the main thing is, what’s the role of Congress in this? And I think in many other instances, we see Congress doing something short of a declaration, like an authorization of some kind. Go back to the Gulf of Tonkin Resolution during the Vietnam War, or the authorization to use military force before the Iraq War, or 2001 in Afghanistan. And so it is often the case that Congress plays some supportive role, short of a declaration. We obviously don't have that here.
“I wouldn't say its not legal,” continued Raustiala, who is Promise Distinguished Professor of Comparative and International Law at UCLA School of Law. “It’s difficult to answer that, because the parameters of Congress’s powers and the president’s powers have ... evolved over time. I mean, even the framing generation understood the idea that the president had the authority to repel sudden attacks, what exactly that means and what role Congress should play has been ... a bit of a struggle, a bit of a dance between the two branches.
“All of that said, I think ... it is certainly a kind of customary practice generally, to seek some degree of congressional approval. But it’s also the case that the executive branch has always resisted the idea that they have to do it. [Y]ou mentioned the War Powers Act. That was [the]1970s era, maybe a high point of Congress’s attempt to claw back some of its control in the wake of President Nixon, and the kind of idea that the presidency was a bit wayward. But the executive branch has always been resistant to it, and always kind of argued either that it doesn't apply, or it isn't fully legal, or they're providing information, but they don’t have to.”
Listen to the podcast here.