Astonishingly, President Trump and his aides were caught unprepared when Iran, under air assault from the United States and Israel, retaliated by targeting shipping in the Persian Gulf region and specifically through the Strait of Hormuz. Military planners have pointed out for decades that the waterway—through which one-fifth of the world's oil and liquefied natural gas passes—is highly vulnerable to Iranian assault. But the Trump administration acknowledged in classified briefings, CNN reported last night, that it did not make provisions for a closure because officials assumed that such a move would hurt Iran more than the United States. In its failure to anticipate Iran's reaction, the administration ignored a dynamic that former Defense Secretary James Mattis, a first-term Trump appointee, was fond of pointing out: Once hostilities begin, "the enemy gets a vote." U.S. leaders have drastically underestimated the Iranian regime's ability to survive, adjust, and strike back. Just tw…