TEHRAN—Just after 1 a.m. in Tehran, my friend and I were still sitting in a crowded café. Hookahs passed from hand to hand. People scrolled through their phones, speaking in low voices that occasionally broke into laughter. Then came the blast, deep and heavy, the kind you feel through the floor before it reaches your ears. Conversations stopped. Heads turned toward the windows. For a few seconds, the room went silent. Then life resumed. In Tehran, this is what war looks like a month into the