how not to get a captured soldier back safely from ISIS

I don't see how publicly threatening "grave consequences" can possible help the pilot. That's practically daring ISIS to do something horrible to him. Which means that the Jordanian government's threat was more for its domestic audience than the pilot's captors. Maybe he was anyway, but I suspect that guy is a goner. And when his execution video inevitably shows up, how exactly is Jordan going to follow through with its threat?