Aaron Blake: “The week began with President Donald Trump saber-rattling like we’ve never seen before. He threatened apparent war crimes and to end a ‘whole civilization’ if Iran didn’t meet his demands.”“It is ending with Trump looking like he’s losing leverage, out of ideas — and increasingly anxious for an offramp.”“The economic news Friday was especially grim for Trump’s ability to keep prosecuting this war and drive a hard bargain with Iran in upcoming negotiations.”