Koh told Lugar, "When the statute talks about the introduction of U.S. armed forces into hostilities, and what you are sending in is an unmanned aerial vehicle high in the sky, it's not clear that that provision was intended to apply to that particular weapon." An hour later, in an exchange with Sen. Chris Coons, D-Del., Koh added: "If we are concerned about unmanned uses of weapons that can deliver huge volumes of violence, a statute which only deals with the introduction of U.S. armed forces does not address that situation." (You can watch the exchange in the hearing video at the two-hour mark.)
That's a pretty clear statement that the War Powers Resolution doesn't apply to drones. The resolution refers to the "use of United States Armed Forces." Koh, representing the administration, says that a statute using this language doesn't address unmanned weapons, even if, in Koh's words, they "deliver huge volumes of violence." So it doesn't matter how aggressive the mission and the means are. The resolution still doesn't apply, because, as Koh explained to Coons, the lawmakers who passed it in 1973 "weren't thinking about drones."
The administration is trying to have it both ways. To soothe Congress, it's implying that under a complex four-factor analysis, there's some level of violence at which a president would need congressional authorization to continue using remotely piloted weapons. But as a textual matter, it's claiming that drones don't need such authorization.
Which is it, Mr. Koh?
Readings I recommend: Several legal scholars have written good articles and blog posts on drones and the law. If you're interested in this topic, check out the ongoing coverage at Lawfare (including these posts), Opinio Juris (including these posts), EJIL: Talk! (including these posts), and Balkinization (including this post). You can find Harold Koh's 2010 analysis of drones, law, and the "use of force" on the State Department website. And courtesy of the New America Foundation, you can watch video of a recent conference on Drones, Remote Targeting, and the Promise of Law.