A panel of experts operating under United Nations authority has formally raised the possibility that recent American military strikes against Iran crossed the threshold into war crimes under international humanitarian law. The allegation places the conduct of those operations under official international scrutiny, invoking centuries-old principles designed to protect civilians and constrain the violence of war. Whether or not prosecution follows, the inquiry marks a consequential moment in which the machinery of international law has been set in motion against the actions of a major power — a