I’m “afraid” this leads toward a principle that some would call venerable and others outdated: don’t use military force without a declaration of war. We’ve become conditioned by events and cliches to believe that if this path is taken again we’ll return to the bad old days when wars were “all or nothing.” But as any good neocon knows, the “bad old days” were actually replete with limited wars; you can just look back to the Spanish-American or the Crimean Wars for pretty good examples of combat among great powers that didn’t turn into shootouts for survival.
The argument could be made that the possibility of limited war perversely increases the likelihood of wars: the extreme, and probably best, illustration of this is the deterrent effect of mutually assured destruction by massive nuclear exchange. But this in itself isn’t a reason to jettison declared war, because insisting upon formal declarations of war forces an “all or nothing” statement as to the character of the conflict. “War” triggers (or triggered) a whole sequence of rules, presumptions, postures, and even laws; “war” also keys in a people to the unique seriousness of the conflict without having to resort to switcho-changeable semantic games. Declaring war is inclined to keep a fighting power more honest than a fighting power that hasn’t declared war.
Declarations of war accomplish one other thing: making it formally clear who is the aggressor and who is not. This isn’t because whoever declares war first is it; it’s because a declaration requires an argument — typically, a written argument — that lays out the reasons why a state of war has been or is being entered into. Since the establishment of the United Nations, states are not supposed to be able to legitimately announce that they’re starting hostilities. But declarations of war under the new model do permit and indeed require states to detail the hostilities they have been exposed to (even and especially without a declaration) such that they must enter into a state of war in order to engage them.
All of which would do a world of good to prevent another absurdity like the way we got into Iraq — an awful muddle of lacunae in international law and sloppy, semi-meaningless US authorization of some kind of forcible something or other. And all of which suggests, then, that the Democrats demanding prior Congressional authorization on any use of force toward Iran are right!
But wait. Will a Democratically-controlled Congress ever authorize force against Iran — particularly of the tightly-controlled variety that under virtually any circumstances is far, far preferable to “all out” war? Or has the modern fear that declaring war means authorizing total war paralyzed them?
Upon those horns the legitimacy of US foreign policy squirms. The trade is that we use force by the book, Constitutionally, formally, as declared War, in exchange for the actionable understanding that declared War is not to be taken as a blank check. Trouble is that now we have to fight against at least some adversaries for whom “limited war” means sending only ten guys strapped with catastrophic weapons across the ocean. We could think that one answer to this problem is to double down and damn the torpedoes, but another possibility is to think out plenty beforehand what exactly it’s worth to us to risk the use of force in Iran. The answer is open. I wonder how many Hezbollah would volunteer to die to avenge twenty-five pinpoint strikes on Iranian nuclear facilities.