Volodymyr Zelensky’s situation room, where the Ukrainian President monitors developments in his country’s war with Russia, is a windowless chamber, largely taken up by a rectangular conference table and ringed by blackened screens, deep inside the Presidential Administration Building, in central Kyiv. On a recent afternoon, as I sat inside, waiting for Zelensky, I heard his voice—a syrupy baritone, speckled with gravel—before he entered, dressed in his signature military-adjacent style: black T...