The power to wage war is the power to wage war successfully.

Hughes’s line compresses a hard-nosed constitutional and strategic idea: a state’s authority to initiate war is inseparable from the practical capacity to carry it through. Read this way, “power” is not merely a legal competence (the formal right to declare or conduct war) but an effective power—organization, resources, unity of command, and public support—without which war-making becomes self-defeating. The statement also implies a warning against half-measures: to embark on war without the means or will to win is to misuse the war power and to invite greater costs. In debates over executive versus legislative control, it can be taken to argue that war powers must be paired with responsibility for outcomes.