WHAT RUSSIa cannot get by fighting it is demanding to be given on a plate through the pressure that Donald Trump can put on Ukraine and on America’s European allies. At the top of Vladimir Putin’s shopping-list is the western part of Donetsk province, which is still firmly in Ukrainian hands. But it is not just the symbolism that is important to him. The real prize is to force Ukraine to abandon its strategically critical “fortress belt”, a 30-mile (50km) line that comprises four cities and several towns, which stands in the way not only of Russia’s goal of gaining the whole of Donbas, but also of its ability to threaten other regions.

Work on the fortress began when Ukrainian forces wrenched back the four cities from Kremlin-backed proxy forces in 2014. The belt runs from Slovyansk and Kramatorsk in the north down to Druzhkivka and Kostyantynivka in the south. Andriy Zagorodnyuk, a former defence minister who now chairs the Centre for Defence Strategies, a think-tank, says that there has been a massive investment in military infrastructure and fortification over the past ten years. Sloviansk, which the Russians tried and failed to seize in 2022, and Kramatorsk are major logistics hubs for Ukrainian forces.
A relatively urbanised area, dense with buildings and industrial sites that form a barrier of their own, the belt has been reinforced with layers of wire, concrete, gravel and concrete “dragon’s teeth”. After the fall of the town of Bakhmut and Ukraine’s failed counter-offensive in 2023, further efforts have been made to build up both passive fortifications, with bunkers and trenches that form a network stretching several miles from front to rear, and active ones, such as minefields and tank traps.
Russia’s main military effort over the past 12 months has been the struggle to take Pokrovsk, some 40 miles south-west of the fortress belt. However, despite some recent territorial gains, the Institute for the Study of War (ISW), a think-tank in Washington, DC, believes that the attempt to envelop and seize the fortress belt from there “would likely take several years to complete”. Nico Lange, a former chief of staff at Germany’s defence ministry, says that it would not only take years to take the fortress belt but would be hugely costly for Russia in terms of casualties and resources.
The loss of the fortress belt as a result of a deal with Mr Putin is unthinkable for most Ukrainians. For one thing, the idea that Ukraine could simply move its front line back and rebuild its defences is not viable. As Mr Lange points out, constructing new defensive positions would be enormously expensive and take a great deal of time because the topography of where they would have to be built is far less favourable.
For another, according to the regional administration, there are still more than 250,000 civilians living in the Ukrainian-controlled parts of Donetsk, including around 18,000 children who would be in danger of abduction if they stayed. Although Slovyansk and Kramatorsk are bastion towns, life there goes on and there is quite a thriving military economy.
But the biggest fear, says Mr Zagorodnyuk, is that once in Russian hands the infrastructure of the fortress belt could in effect be turned against Ukraine and used as a launch pad for further aggression. “Every settlement in the nearby regions, including Dnipropetrovsk, would be in enormous danger. The Russians know this very well.” The ISW agrees: “Conceding the remainder of Donetsk Oblast [province] would thus also provide Russian forces more advantageous positions from which to attack into Dnipropetrovsk Oblast.” Mr Lange argues that a takeover of the fortress belt would “open an operational route to the rear of the city of Kharkiv and towards the city of Dnipro on the banks of the [Dnieper] River, and thus into central Ukraine.”
For many Ukrainians, giving up the fortress belt without a fight would be tantamount to capitulation and a betrayal of the sacrifices of its armed forces. Few believe that Russia will stick to any undertakings not to continue the war when it suits it to do so. Nor is it likely that security guarantees that are dependent on Mr Trump’s consistency and reliability will be seen as adequate compensation. However, as Mr Lange points out, such security guarantees would be a lot more convincing if they are combined with Ukraine’s current defensive positions rather than if the fortress belt is handed over to the invaders.