Crowning a year of disputes with the Trump administration over trade tariffs, support for Ukraine and the future of Greenland, the Iran war has placed America’s friends in Europe, Asia and the Middle East in front of an uneasy dilemma. Their most important ally is acting in ways that they see as erratic and that have already caused hardship and uncertainty. The war has sapped their economies and even bigger shocks loom if the Strait of Hormuz remains closed, deepening the worldwide energy crisis. Many—on both sides of the Atlantic—wonder if they are even allies anymore. Angered by the refusal…