THE one hospital for the Russian city of Donetsk (not to be confused with the larger Donetsk in eastern Ukraine, 135 miles away) sits just a few miles from the border with Ukraine. Around 5pm on August 17th I was standing outside when a convoy of vehicles sped up to the entrance. Out spilled around 40 rebel fighters injured in battle against pro-Ukrainian forces. They had set out on the six-hour drive through eastern Ukraine and into Russia that morning. There was a man missing a leg, its stump wrapped in plaster; another had a large head wound, his eyes glassy and vacant. Several had the red pockmarked scars of shrapnel. They had been expected. Medics from the Russian emergencies ministry, along with a handful of Federal Security Service (FSB) officers, walked among the minibuses that delivered the fighters and began to process the injured. The FSB officers questioned them about their wounds and experiences in the war, taking notes and handing the fighters forms to sign. A dozen or so would stay in the trauma ward here; the rest were sent in waiting ambulances for treatment at hospitals throughout the Rostov region.

In recent days, the area around the border crossing of Izvarino—the hospital is just down the road—has come under heightened attention as Moscow dispatched a column of nearly 300 trucks with humanitarian aid meant for the besieged city of Luhansk. Although the details remain unclear, it appears they will pass through Izvarino and into rebel-held territory after being checked by officials from the Red Cross. The trucks' progress has been held up, whether by design or as a result of diplomatic wrangling, and appear to be a sideshow rather than the beginning of wider Russian intervention. Nonetheless, their presence has provided a chance to look at the war in eastern Ukraine from the other side of the border, a stretch of territory that functions as a kind of rear base for supplies and medical care for rebels and civilians.

Near the bus depot where 16 of the approximately 270 trucks wait for Red Cross inspection, another sort of humanitarian mission was awaiting its turn to cross the border. A dozen women from Luhansk—a city that has been without water, electricity or regular access to food for weeks—had come to stock up on supplies to bring back to their families. They were sleeping in the white bus they had loaded with provisions, waiting for the all-clear that the road was safe to travel. It had been three days. One woman, Natalia, said she could talk to her husband back in Luhansk only when he was able to climb a hill with the one remaining mobile-phone tower. “We’ve been going through this for two months...Every day they bang away,” she said, blaming Ukrainian forces for the shelling of the city. Every now and then the hot summer air was pierced by the boom of artillery fire on the other side of the border. Plumes of black smoke wafted up from the hills.

The border area is full of rebel fighters moving in both directions. Vans with the insignia of the “Donetsk People’s Republic” and “Novorossiya” make their way along the dirt roads that run alongside and into Ukrainian territory. On the official crossing at Izvarino, Paul Ricard, a monitor from the Organisation for Security and Co-operation in Europe (OSCE), regularly sees young men in military-style dress crossing the border. Around dusk one night this week, I watched as a dozen men in fatigues with patches for various rebel brigades, including the “Russian Orthodox Army”, waited on the curb at Izvarino for minibuses that drove them into Ukraine.

In the hospital in Donetsk lay Yuri, a 52-year-old retired miner who goes by the nickname “Kolyvan”, the name of a Russian fairytale warrior. Yuri lost his left arm and leg when a rebel checkpoint he was guarding came under rocket and mortar fire on July 2nd. He was lying in a bed near the window, every now and then lifting himself up on a metal pole with his remaining arm. “My only entertainment is the clouds,” he said. Yuri is from Bryanka, a city of 50,000 people near Luhansk. “I never wore a balaclava, I never hid my face, I was on my own land,” he said. The war is fought not so much along ethnic lines as historical ones, he argued. “Our heroes are different”: those in the Donbass revere the Soviet military commander, Georgy Zhukov, whereas “for them”, figures like Stepan Bandera and Roman Shushkevich, two Ukrainian nationalist militia leaders from the second world war, are considered heroes. Kiev may consider him a terrorist, Yuri said, but there are “millions of people like me”.

Some can be found in a hospital in Kamensk-Shakhtinsky, a town 20 miles from Donetsk. Upstairs, in the sweaty, third-floor trauma ward, where almost everyone lay in bed in their underwear for some relief from the heat, a muscular 21-year-old rebel with the nickname “Meteor” spoke to me in the hallway. He was a police officer in the Donetsk region, a former member of the Berkut, the now-disbanded division that did battle with protestors on the Maidan last winter. He wasn’t entirely unsympathetic to their cause, he said. “I supported their slogans, but not their methods.” After the fall of Viktor Yanukovych, he planned to move to Crimea, recently annexed by Russia. But then some friends joined up with the rebel militia, and after he watched scenes of horrific violence in Odessa on May 2nd, he couldn’t remain “indifferent”.

On July 26th his convoy of anti-Kiev fighters, which had gone in search of medicine, fell into an ambush laid by Ukrainian forces. He was shot through the arm. Rebel commanders have told him he is up for an award for bravery in combat. The war has been far from glorious for him, however: his father joined the rebel militia in June and was killed in a Grad rocket attack a month later. “That’s how I know he was a real man,” he said.

All the injured rebels I spoke to in Russian hospitals near the border were from Ukraine, most from the Donetsk and Luhansk regions that are home to the anti-Kiev insurgency supported by Russia. That is not to say Russian fighters do not exist: several told me of comrades who joined the war from the Russian cities of Kursk, Rostov, Tomsk, and even Vladivostok, on the Pacific Ocean. (On August 15th a rebel leader claimed he had received 1,200 fresh soldiers who had been trained in Russia.) Very few expect or hope for direct Russian military intervention. Their sense of grievance and revenge has only deepened as the war has dragged on: what began as suspicion of Kiev and its motives has turned to hatred as they have seen friends killed in battle. “Meteor” said that on his second day in the militia, a fight at a checkpoint controlled by Ukrainian forces left two fellow rebels dead. “After that, I wasn’t able to leave. I already felt responsible,” he said.

Even if Kiev and Moscow—shepherded by the West—reach a negotiated agreement to end the war, it is unlikely the impulses that drive the conflict will disappear. Whether fuelled by propaganda or the scarring experience of battle, the certainty in the righteousness of the rebel cause has hardened into something unshakable. Before I left his bedside, I asked Yuri if he would move back to his hometown in eastern Ukraine after the war is over. “How can you return to a fascist country?” he asked. “Only with weapons.”