he war in Iran has emphatically demonstrated American military might on the world stage. There is only one superpower in the world today, and it isn’t headquartered in Moscow, Beijing or London. Alongside Israel, the United States has decimated much of Iran’s defenses, air force, navy, ballistic missile sites, nuclear infrastructure, and its political leadership. All in the space of just three weeks. The Iran war has also sharply exposed simmering deep-seated tensions in the transatlantic alliance, as well as the open cowardice, petulance and weakness of European leaders, including among its increasingly diminished major powers—principally the UK, France and...