The other day Jon Chait approvingly cited the Clinton administration maxim that the United States would be “Multilateral when we can, unilateral when we must” with regard to the use of force. That sounds very wise and sober-minded compared to my nutty view that we should, going forward, strive to act in accordance with international law. But like a lot of wise and sober-minded verbal formulae it doesn’t really mean anything. After all, nobody’s ever going to say “we must use force unilaterally, but we shouldn’t.” That’s a contradiction. To say that we’ll act unilaterally when we must is, like the similarly wise and sober-minded notion that we should be willing to use force to advance our vital national interests, simply to avoid the question — namely when must we act unilaterally?
Now observing that this kind of talk is vacuous doesn’t show what standard we should use. But people, including Democrats and liberals, who believe that there should be no external or procedural checks on American use of non-defensive military force would do well to say so rather than hiding behind tautologies. I don’t think that’s a doctrine that will serve the United States well as we move forward into a less-unipolar world.