From a line of trees the Ukrainian gun team prepares to fire. An artilleryman, Yurii, loads a 152mm shell into an old Soviet-made howitzer. “We are ready!” Yurii says. He moves away from the barrel. “Fire!” the unit’s commander replies. There is an almighty boom. White smoke fills the dugout, which is hidden beneath camouflage nets and cut pine branches. From the undergrowth, a chiffchaff resumes its spring warbling. Nearby, in the north-east of Ukraine, Russian troops were trying to advance. In February 2022 they rolled in to the town of Dvorichna at the beginning of Vladimir Putin’s full-scale invasion....