According to BBC reporting, US Central Command has confirmed that Iran-backed proxy groups launched attacks against American bases and Saudi energy infrastructure, prompting joint US-Saudi strikes in response. I will take the account as given and reason from there, marking anything beyond that lead as inference.

The first question a treaty-minded observer must ask is not whether the response was forceful, but whether it was grounded in obligation. A strike conducted jointly by two nations carries a different character than one conducted unilaterally. It signals that the parties stand upon a common understanding — some arrangement, formal or tacit, that makes their shared action lawful in their own eyes and, ideally, explicable to the community of nations. Whether any such formal convention between the United States and Saudi Arabia fully supports joint offensive operations is not disclosed in the report, and I will not pretend to know its terms. That, however, is precisely the question Congress and the public ought to press.

I learned through long experience — at Paris, and later in the difficult negotiations with Britain — that the language of a treaty is not decoration. It is the whole of the matter. When parties argue afterward about what they agreed to, every ambiguous word becomes a wound. If the United States has extended to Saudi Arabia something resembling a security guarantee, the scope of that guarantee should be written plainly, ratified through proper constitutional process, and understood by the citizenry that will bear its costs. Inference is not a treaty.

There is, further, the question of proxy warfare itself. International law — the law of nations, as my generation called it — has always struggled with the fiction that a sovereign is innocent when its armed clients do the fighting. The doctrine of state responsibility holds, in principle, that a state cannot escape accountability by routing its aggression through irregular forces. Whether the evidence linking these groups to Tehran meets that standard is a matter I cannot adjudicate from the outside; but it is the standard that must be applied, soberly and in public, if the response is to rest on law rather than mere retaliation.

I would counsel this: before the next strike is ordered, let the executive lay before Congress and the public the precise legal basis for collective action — which convention, which article, which construction of self-defense under the law of nations. Proportionality is not only a military calculation; it is a legal one. A republic that makes war without explaining its warrant to the governed has borrowed against a credit it may one day find exhausted. The strength of the public faith, at home and abroad, depends on the clarity with which the nation's obligations are stated — and honored — before the cannon sounds, not after.