The killing of a top Iranian general has ratcheted up the anxiety of families of Americans held in Iran. Just a month ago the release of a New Jersey student had given them hope. The Trump administration has made a priority of bringing home hostages held abroad. But the prospect of a speedy resolution for the handful of captives in Iran seems to have dimmed with the two nations edging dangerously close to conflict and warning of retaliatory strikes. It’s a contrast from December’s release of a Princeton University graduate student in a prisoner exchange.