Russia is fighting Ukraine about borders. This means that, as well as dodging bombs and getting used to living in the dark, residents of the border zone have to decide if they are ‘really’ Russian or ‘really’ Ukrainian. Some will no doubt be keeping the non-chosen identity in a trunk in the attic, to be retrieved in case of future need. But the logic of war is stern: those who choose to be Ukrainians are also opting to hate Russians as the enemy invader, while those in Ukraine who choose to be Russians are contemplating the possibility of having to move east.