The morning that Russian bombs started falling on Kyiv, Oksana Bruy woke up worried about her laptop. Bruy is president of the Ukrainian Library Association and, the night before, she hadn’t quite finished a presentation on the new plans for the Kyiv Polytechnic Library, so she had left her computer open at work. That morning, the street outside her house filled with the gunfire of Ukrainian militias executing Russian agents. Missile strikes drove her into an underground car park with her daughter, Anna, and her cat, Tom. A few days, later she crept back into the huge empty library, 15,000sqft once filled with the quiet murmurings of readers. As she grabbed her laptop, the air raid siren sounded and she rushed to her car.

Thanks to that computer, Bruy could work. She didn’t return to her office; instead, she fled west to Lviv. “In all that time, from the first day of the full-scale war, I did not stop working,” she says. The library’s IT specialist lived in the neighbourhood. He kept the servers running and the employees connected. “So there was not a single day’s break in the work of the Kyiv Polytechnical Library, all this time, from 24 February.” The Russians have not shut her down. Oksana Bruy is winning her battle in the Ukrainian war. The libraries are open.

The battles of the 21st century are hybrid wars fought on any and all fronts: military, economic, political, technological, informational, cultural. Often ignored, or relegated to marginal status, the cultural front is nonetheless foundational. The wars of this century are wars over meaning. As American forces learned in Iraq and Afghanistan, if you lose on the cultural front, military and economic dominance swiftly erode. The terrible battles for Kyiv and Kharkiv, the destruction of Ukraine’s civilian infrastructure, Europe’s struggle to heat and feed itself this winter, spiralling inflation, the brutal material horrors of the struggle, might make any cultural reading of the conflict seem fantastical or glib. But at its core, and from its origin, this Ukrainian conflict has been a war over language and identity. And Ukraine’s libraries are the key.

There has never been a war in which poetry has mattered more. In the earliest days of the invasion, the Russian film star Sergei Bezrukov gave a sensational reading of Alexander Pushkin’s 1831 masterpiece, To the Slanderers of Russia, on his Telegram channel. That great poem is a warning to foreigners about involving themselves in Eastern European wars. “Your eyes are all unable to read our history’s bloody table,” Pushkin warned two centuries ago. “Slavonic kin among themselves contending, an ancient household strife, oft judged but still unending.” In response, the Ukraine rapper Potap posted: “I understand that quote is a classic,” he rhymed. “You are not brothers but enemies.” Bezrukov was saying to the west: “You don’t understand.” Potap’s answer was to Russians: “No, you don’t understand.”

Bezrukov and Potap were both commenting on the distinct interpretations of their political leaders. Three days before the outbreak of hostilities, Putin offered what amounted to a historical dissertation as a declaration of war. His argument was that Ukraine was a fiction, “entirely created by Russia” without “the stable traditions of real statehood”. Ukrainian identity was the result of a western campaign “to distort the mentality and historical memory of millions of people”.

Volodymyr Zelenskiy countered Putin’s history with his speech to the European parliament, an act of rhetoric so powerful that it changed the course of a war, insisting, not only that Ukrainian identity existed, but that it was European in nature. Most wars are fought over who will define the future. The Ukrainian war is a struggle over who will define the past. Is Ukrainian identity real or a fiction? That is the fundamental question of the conflict. The Ukrainians have given their answer.

The libraries are on the frontline. The Russians targeted them from the beginning. In the initial invasion, Russian forces demolished the state archives in Chernihiv, a target containing sensitive NKVD and KGB information about Soviet-era repressions that the Russians wanted erased from the historical record. They ransacked the archives in Bucha just as they looted every cultural institution they conquered. They gutted the archival department in Ivankiv for no good reason. “Those who burn books will eventually burn people,” the German poet Heinrich Heine said. But in the Ukrainian war, the Russians burn books and people together.

Anatolii Khromov is the head of the Ukrainian State Archives – repositories not only of important cultural and historical documents but also of birth and death certificates, marriage and divorce notices, property and insurance records, in short the transactions that constitute a nation. Khromov began as an archivist for the Odesa region 10 years ago. Currently, he lives in an undisclosed location for his security. While Bruy’s laptop stayed open in Kyiv, Khromov was evacuating the state archives from Donetsk and Luhansk. These were the first, but certainly not the last, of the wandering libraries of Ukraine.

The work of the state archivists during the course of the Ukrainian war is simple – to keep what they have out of Russian hands and in existence. “Our mission is crucial because the destruction of archives can be seen as part of cultural genocide,” Khromov says. Russians have destroyed more than 300 state and university libraries since the start of the war. In May, the National Library conducted an online survey on the state of its system. By then, 19 libraries were already completely destroyed, 115 partially destroyed and 124 permanently damaged. The Russians have destroyed libraries in Mariupol, Volnovakha, Chernihiv, Sievierodonetsk, Bucha, Hostomel, Irpin and Borodianka, along with the cities they served. They have destroyed several thousand school libraries at least.

“On 24 February, we began to fight for our national memory,” Khromov says. The fight for national memory took on two forms – the preservation of physical artefacts and the rapid digitisation of the archives that exist. National treasures, such as the birch bark manuscripts of the early Slavonic period or the original paintings and manuscripts of poet Taras Shevchenko, survive safely in flame-proof containers. The problem of large archives was more complex. At the outbreak of war, the state archives were only 0.6% digitised and several went offline because the people paying the bills had been killed or displaced. Their preservation required rapid mobilisation.

The Ukrainian military has distinguished itself in this war by a flexible entrepreneurial spirit combined with an extraordinary ability to mobilise international support. So have the warrior librarians. Anna Kijas, a music librarian at Tufts University in the US, tweeted on 26 February her plans to hold a “data rescue event” for Ukrainian archives. Colleagues at Stanford and the Austrian Centre for Digital Humanities and Cultural Heritage stepped up, and together they launched Saving Ukrainian Cultural Heritage Online, or Sucho, on 1 March. By the end of the first week of that month, Sucho had more than 1,000 volunteers, many working 12-hour days on furlough from regular jobs. By the middle of March they were coordinating with the Ministry of Culture in Ukraine, the International Federation of Library Associations, the International Council of Museums and the Memory of the World division of Unesco. The Jewish material they saved is extraordinary on its own: from prewar musical archives to 400-year-old Galician manuscripts to texts produced by Jewish presses from Volhynia and Bukovina. There is also archeology of the Tauric Chersonese site, a Greek colony founded 2,500 years ago on the Crimean peninsula, the materials in the Bulgakov Museum in Kyiv, and the records of the Ukrainian Centre for Cultural Studies, a documentary repository of song styles and recipes. There were dozens of archives like these in desperate need of preservation.

After the initial rush to preserve, the volunteers at Sucho began working to provide the necessary equipment for local archivists. The Ukrainian military needs air defence systems. The librarians need Epson flatbed scanners, which go for €5,000, and Nikon SLR cameras which cost €3,250. Sucho is currently training librarians, too. They provide backup as well as teaching archival work. The Ukrainians need to digitise an estimated 86m files. So far 50TB of data have been archived due to this massive collective global effort.

Smaller, nimbler organisations are at work, too. Cat Buchatskiy, 21, an international security student at Stanford, founded the Shadows Project, which, before the war, worked to alter the historical record to support a Ukrainian rather than a Russian reading of cultural history, arguing, for instance, that museums should describe the suprematist painter Kazimir Malevich as a Ukrainian artist rather than a Soviet one. In February, she suspended her semester at Stanford and started raising money for bombproof cabinets and fireproof blankets. Ukraine libraries also need more basic supplies, like generators and cardboard boxes.

Last spring, Buchatskiy personally delivered 13 armoured cabinets in a truck from Poland. She often just showed up at the library doors. Sometimes, the librarians didn’t believe this young woman was arriving with highly specialised equipment. Buchatskiy could only convince one librarian, who didn’t quite believe the offer of free fireproof safes, with pictures of a delivery to another library. “Actually, we’ll take 65,” Buchatskiy remembers her saying after seeing the evidence.

Buchatskiy’s greatest tool for distributing equipment is the Ukrainians themselves. “Everyone is helping out one way or another,” she says. When she couldn’t deliver material to one library, she asked a friend, who also couldn’t do it, but her grandmother could.

Meanwhile, the business of libraries continues despite the physical destruction. They maintain the logistical network of Ukrainian culture. “The libraries follow their readers anywhere,” Bruy says. “So in Kharkiv, which is very often bombed, a lot of people live in the metro.” Librarians bring the books to them. People need to read in bomb shelters, too. That’s where they most need to read. “The library isn’t a building,” Bruy says. “The library is a community.”

During this war, Ukrainian libraries now serve new roles. They operate as centres for displaced persons. They offer psychological counselling for traumatised populations. They provide space for art therapy. “Of course, we pay special attention to children,” Bruy says. The librarians even sew camouflage nets when they have the time. But the libraries have two principal tasks to undertake. The first is to keep an accurate record of Russian brutality. “We are convinced that collecting, organising and preserving documents about this war is the straight duty of librarians,” Bruy says. They are also responding to an unprecedented demand for Ukrainian language lessons. Nearly a third of Ukrainians speak Russian as a mother tongue. The war has clarified to them that it is not their language.

Invaders never understand the cultural framework of the countries they invade. If they did, they wouldn’t invade. The US military’s official history of the Iraq war blamed the defeat there, in part, on “gaping holes in what the US military knew about Iraq. This ignorance included Iraqi politics, society and government – gaps that led the United States to make some deeply flawed assumptions about how the war was likely to unfold.” During the war in Afghanistan, anyone who read the poetry of the Taliban would have known they would never concede, no matter how outmanned or outgunned. They were fighting for the birds in the sky and the flowers in the mountains, for the possibility of love itself. A meaningful peace with them was always going to be impossible.

The current Ukrainian war is the military manifestation of a linguistic and cultural struggle that has been ongoing since the 19th century, a struggle between two visions of the Russian-Ukrainian relationship, articulated by the countrys’ foundational poets, Alexander Pushkin and Taras Shevchenko. Pushkin, in To the Slanderers of Russia, pictures the two countries as fratricidal brothers, part of one big murderous family. In his early masterpiece, Caterina, Shevchenko imagines a Ukrainian girl who is seduced and then abandoned by a Russian officer: “O lovely maidens, fall in love, / But not with Muscovites, / For Muscovites are foreign folk.” In Pushkin, Russia loves Ukraine to death. In Shevchenko, Ukraine pulls away from Russia’s fraudulent love for the sake of self-preservation. These remain the conflicting visions of national interrelation 150 years later.

Russian hatred for Shevchenko is durable. In 1992, Nobel prize winner Joseph Brodsky wrote On Ukrainian Independence, a poem of rage and loathing which he never published. The work possesses a deep desire for the destruction of Ukraine: “Hurry back to your huts to be gang-banged by Krauts and Pollacks right in the guts.” But On Ukrainian Independence is a bizarre kind of love song, too, like the rageful cry of an abandoned husband: “Our love is up, if it at all existed.”

Putin embodies the political expression of this murderous love. On 4 October, he gave a speech at a teaching awards ceremony: “We always, and even today despite the current tragedy, hold great respect for the Ukrainian people, Ukrainian culture, language, literature, and so on,” he said. Days later, Russian forces shot the conductor Yuriy Kerpatenko in the head because he refused to play chamber music in Kherson under occupiers’ orders. That’s what “great respect” means for Putin.

The final lines of Brodsky’s On Ukrainian Independence are its most searing and its most prophetic, an address straight to the Ukrainians: “When it’s your turn to be dragged to graveyards, / You’ll whisper and wheeze, your deathbed mattress a-pushing, / Not Shevchenko’s bullshit but poetry from Pushkin.”

Brodsky’s prophecy has come true, but not in the way he expected. The current war is about whose poetry will ultimately be whispered over all the pointless slaughter. No one can say who will have the last word. But one of the first images that emerged after the liberation of Balakliia was Shevchenko’s statue with a Ukrainian flag raised over it. In response to Ukrainian incursions into Donbas, Russian missiles hit the playground in Kyiv’s Shevchenko Park.

In the war over meaning, the Russians lost on the first day. Their contention that Ukrainian identity doesn’t exist has been proven wrong no matter what happens now. The question that remains is not whether Ukrainian identity exists, but whether Russia can annihilate the Ukrainian identity it claims is nothing more than a distortion. Their assault on Ukrainian libraries has only increased as the war has developed into an act of the mass terrorisation of civilian populations.

In Kyiv on 10 October, the Russians bombed the Maksymovych Scientific Library of the Taras Shevchenko Kyiv National University, Vernadsky National Library of Ukraine, the National Scientific Medical Library of Ukraine and the Kyiv city youth library. Defiance radiates off Oksana Bruy. “Maybe the Russians think we will be scared of their Shahed drones and rockets,” she says. “We just do our work every day.” On 30 September, Ukraine celebrates an “All Ukrainian Library Day.” This year it unveiled a new motto: “The library is unbreakable.”

The Ukrainian war has been, so far, a massive, catastrophic act of misinterpretation. The Russian elites convinced themselves that Ukrainian identity wasn’t real. Their actions from the outset of the conflict genuinely seemed guided by the assumption that Ukrainians would not resist, that they would submit to be subsumed, that they didn’t believe the story of their own independence. The Russian invasion is more than a symptomatic failure to understand Ukrainians’ distinction from Russian culture, though. It also has accelerated the separation.

Ukrainian culture in the future will be inherently anti-Russian. “We must forget there is such a country,” Bruy says. Cat Buchatskiy points out the brutal irony of the moment: the war against Ukrainian identity has forced Ukrainians deeper into their identity. “We would never have come to this place if we did not have a gun to our head,” she says. “It has taken a war to bring all these people together.” No one has done more for the development of Ukrainian culture than Vladimir Putin. He has proven, more than any other figure, that Ukrainian culture is distinct and vital.

Culture is not a luxurious decoration on top of politics; it is the basis of collective existence. Several battlefield commentators have noted the difference between the strength of Ukrainian morale and the absence of Russian morale. But morale is too blunt a term. The question is more accurately: “Who would want to be part of the Russian story?” In September, when Putin released his military draft order, hundreds of thousands of Russians gave their answer by fleeing. They’d rather be part of the Kyrgyz story, or the Armenian story, or the Georgian story.

Meanwhile, Anatolii Khromov is hiring. There’s a new position in the Transcarpathian library system. Reading rooms are starting to open. They are resuming the work of libraries, which is to build cultures day by day, room by room, book by book. Libraries exist because the precious things they shelter – words, meanings, communities of readers – need sheltering. The precariousness of culture does not mean weakness, though. Cultures flourish in peace but define themselves in resistance. In the 21st-century wars of meanings, you do not want to be up against the librarians. They keep meaning alive.

• This article was amended on 4 December 2022. An earlier version incorrectly described Kazimir Malevich as a “supremacist”, rather than a suprematist, painter.