WASHINGTON — President Trump says the U.S. Navy is clearing Iran ian mines from the Strait of Hormuz , a vital sea route for oil shipments whose disruption is increasingly threatening the global economy. Sweeping for underwater explosives could take months despite a tenuous ceasefire between the United States and Iran in the weekslong war, experts say. Any future claims that the U.S. cleared the waterway where 20% of the world’s oil typically passes might fail to convince commercial freighters