“Until you’ve been there, you don’t know what war is.” This short, intense memoir of Yeva Skalietska is the record, told in diary form, of the transformation of the life of a 12-year-old Ukrainian girl from Kharkiv. Yeva writes in direct, unadorned prose – she enjoyed learning English at school and the poise and precision of her language are extraordinary, given her age and the fact that she has constructed this record in words she has only ever encountered in the classroom or on television. Yeva lives with her grandmother, Iryna, in an apartment on the outskirts of Kharkiv. From her window, she can see “huge empty fields that lead on to the Russian border”. We get a brief snapshot of her prewar life: parties, painting, tenpin bowling. It’s a vision of normality that is shattered by the events of 24 February 2022. There’s something extraordinarily immediate and intimate about the way that this book is constructed. The diary is illuminated by photographs of Yeva taken by her grandmother, in which you can see the strain and fear begin to etch themselves on her face. There are also excerpts from Yeva’s class WhatsApp group. She and her grandmother watch missiles flying over their home and then rush to the relative safety of the basement. Bombs become part of the fabric of their lives, a nightly terror that sends them underground and elicits messages of heartbreaking hope and solidarity between Yeva and her classmates. More heart-rending still is to be privy to the author’s thoughts (and those of her friends) as the city they love, a city of parks, monasteries and beautiful old buildings, is destroyed. When Yeva’s beloved apartment is hit by a missile, she and her grandmother decide to leave. Just before they depart, they meet a Channel 4 reporter and Yeva gives an interview that becomes one of the signal moments of those early days of the war, with clips shared over social media. She is briefly famous. Yeva and her grandmother make their way across Ukraine, through Budapest, and then to Dublin, where they are given refuge by a big-hearted couple, Gary and Catherine. At the end of the book, we read brief snapshots of the lives of Yeva’s friends, whom we have come to know through the WhatsApp exchanges. It’s hard to get through this section dry-eyed. At a time when “Ukraine fatigue” appears to be settling in, You Don’t Know What War Is feels like required reading. You Don’t Know What War Is: The Diary of a Young Girl from Ukraine by Yeva Skalietska is published by Bloomsbury (£9.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply