A U.S. attack or a move to seize control of Iran’s main oil export hub could cripple the country’s ability to profit from its natural resources. But it would also risk sending energy prices even higher. Donald J. Trump told an interviewer in 1988 that if Iran attacked U.S. forces, “I’d do a number on Kharg Island. I’d go in and take it.” Nearly 40 years later, the fate of Iran’s main oil export hub, an island that Mr. Trump now calls the country’s “... [1553 chars]