Like all red-blooded national security law nerds, I have been following Jack's excellent posts over the past week on the politics and the advisability of a potential ISIS AUMF---the last of which post, which ran yesterday, offered strategies for narrowing a potential authorization to make it more politically doable. Jack writes: "One way to make an IS authorization politically palatable to both the President and Congress is to make it narrow."
Towards this end, Jack offers several legislative strategies: (1) authorizing force only against ISIS, (2) limiting the authorization geographically, (3) making plain that ground forces are not authorized, and (4) including a sunset provision. Jack does not treat the question of whether a narrow ISIS authorization is, on the merits, a good idea, regarding narrowness as a political necessity for getting a resolution passed. On this point he is probably right, but it's worth at least pausing over the question of what sort of AUMF in the abstract makes most sense. Putting political palatability aside for the moment, I don't think a narrow one of the type Jack describes is ideal.
The main reason to prefer a broader instrument is flexibility and agility. ISIS arose rather suddenly. Only a few months ago, the group everyone was talking about was AQAP. And remember AQIM and Al-Shabaab? The threat environment we face is very fluid---mutability, to paraphrase Shelley, being the only constant. An instrument that authorizes force in a specific location against a specific group will very likely become irrelevant quickly. This is, of course, a virtue if your main goal is to constrain executive flexibility. But constraint on the executive is only one relevant goal here. Jack and I---along with Bobby and Matt---were arguing for a more flexible and accountable AUMF long before the current debate over an ISIS authorization arose. Those arguments still stand, and while the politics may militate against consolidating the question of what to do about ISIS with the larger question of what to do about next-generation extra-AUMF threats, the better way to think about ISIS---in my view, at least---is to regard it as the most developed and threatening example of the larger problem of emergent threats that, to one degree or another, the 2001 AUMF addresses badly.
The consequences of a narrow AUMF of the type Jack describes, I fear, would be merely to defer, not to answer, the larger questions about how structurally to deal with congressional authorization for these emergent threats. The next time one crops up, the administration will either have to be back knocking at Congress's door---hardly ideal for a Congress that, as Jack rightly notes, wants to avoid accountability by not voting---or will have to operate on the basis of inherent Article II authority, which is not desirable for a lot of reasons. That is to say, we'll be right back where we are now.
The much better approach---whether it's politically doable or not is a different question---is to put the whole enterprise on a statutory basis and sunset the whole thing, thus making the structure itself time-delimited but flexible within the period of authorization.