When treaties break, cannons speak — and nations pay

The BBC reports a stark sequence: an attack on a cargo ship, an American military strike on Iranian targets, and Iran's counter-allegation that the United States itself violated the terms of an existing agreement between the two parties. I cannot speak to the precise language of that agreement, having had no occasion to read it; I can speak only from the shape of the thing, and that shape is one I have seen before.

A cargo ship is not merely property. It is a vessel of commerce moving on waters that belong, by the law of nations, to no sovereign. The freedom of that navigation is not a courtesy extended by strong states to weak ones; it is a principle upon which the trade of republics depends. When I negotiated with Britain in 1794, the central wound was exactly this — the seizure of American merchant vessels, the impressment of sailors, the treatment of neutral commerce as a belligerent's prize. The principle then, as now, was that a nation's goods moving on open water deserve protection, and that attacks upon them are not merely commercial injuries but affronts to sovereign dignity.

Yet the more consequential question raised by the BBC's account is the one Iran has placed before the world: that the United States acted in breach of an existing agreement. I will not adjudicate that claim — I lack the text of the deal, the record of its negotiation, and the facts on the ground. But I counsel this much: the allegation must be answered with argument, not silence. A nation that ignores a treaty accusation invites the world to assume the accusation is true. The public faith of a republic is not a domestic matter; every trading partner, every neutral power, reads the record and draws conclusions about whether this nation's word holds.

This is the peril of conducting foreign policy through force before exhausting the architecture of obligation. If a deal exists — however imperfect, however extracted under pressure — its violation by either party dissolves the one restraint that stood between dispute and open conflict. I learned this negotiating the Treaty of Paris: a bad agreement faithfully honored is, in most circumstances, preferable to a good agreement treated as optional. The moment parties begin selecting which clauses bind them, the entire instrument loses its authority, and you are left with nothing but competing grievances and matching arsenals.

What should be done now is precisely what is hardest to do in the heat of a military exchange: return to the text, publish the terms of the existing agreement, submit the competing breach allegations to whatever neutral mechanism the agreement provides — or, failing that, to the judgment of the international community — and negotiate an explicit, written understanding about the protection of commercial vessels in the affected waters. Navigation rights secured by treaty are more durable than navigation rights secured by patrol. Force can hold a sea lane for a season; law, carefully written and faithfully kept, can hold it for a generation.