Kiev. Sirens wail. I jump up in bed and try to shake my friend Alex awake. “Wake up! Air alert. Let’s get to the shelter! Hurry up!" He turns away. "Let me be! This shit alarm is constant." I dress hastily. He sighs, wearily grabs his cell phone and checks a warning app. "Nothing serious! No bombs! At least not yet,” he says calmly, rolls over and goes back to sleep. Now I'm calming down a bit. I feel a bit ridiculous—an outsider who doesn't know anything about war. I'm staying for a few days with my Ukrainian friend Alex, who I've been friends with for a number of years, although we often...