Last May, U.S. President Donald Trump paid a triumphant visit to Saudi Arabia, Qatar, and the United Arab Emirates. Over the course of a four-day tour, he admired the Gulf capitals’ “gleaming marvels,” cheered on their ambitious modernization plans, and showcased over $3 trillion in pledged Gulf investment and “mega-deals” between U.S. and Gulf businesses. What a difference a year makes. For weeks after the United States and Israel began their attack on Iran , on February 28, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates all faced barrages of Iranian missiles and drones aimed at military bases, airports, oil refineries, and data centers. On April 8, a cease-fire stopped most of the fighting, but Iran has effectively blocked the Strait of Hormuz, halting shipping of Gulf oil, gas, and other commodities. The problem Gulf leaders now face is broader than the status of the Strait of Hormuz.…