Why the battle for Donbas will be very different from the assault on Kyiv

The tragedy discovered amid the rubble of Bucha and Borodianka overshadowed any jubilation that Kyiv had defeated Russian forces that had spent a month trying to envelop the capital and snuff out the Ukrainian nation. Nevertheless, the defeat of Russian forces in the north marks a turning point in the war. For the medium term, Ukraine will now survive. But for its soldiers there is no respite, for having had its first objective denied Moscow has turned its gaze on the Donbas, where a major offensive is imminent.

The Donbas has been at war for eight years. More than 90 Ukrainian soldiers were killed in 2021 defending the line of contact. Since late February Ukrainian positions have come under regular artillery fire, with mobilised civilians from Russian-occupied Donetsk and Luhansk pushed into attacks on the Ukrainian trenches. The aim of this Russian activity was to fix the 40,000 Ukrainian troops in the Joint Forces Operations (JFO) area, preventing them from impacting the fights for Mariupol, Kharkiv or Kyiv.

The battle will be very different from the advance on Kyiv. Russian units at the beginning of the war were not ready or supplied for heavy fighting. Now the Russians appreciate what they are up against and with only two axes to support can concentrate their supplies. Russian air defences have good coverage over the Donbas and they will likely be able to bring significant air power to bear. Combined with their advantage in artillery, and the fact that the fighting will be in the countryside rather than into urban centres, Ukrainian troops will need to manoeuvre to survive.

For the Ukrainians the next month will be costly but potentially decisive. If Russia seizes the Donbas it can go firm and can pause while it brings up reserves for a summer offensive. On the other hand, if Russia fails to hit its objectives then many of its units will find themselves thrust forwards and exposed, at risk of persistent attrition like the troops who recently retreated from Kyiv.

For the Ukrainian military the priorities for the battle in the Donbas differ slightly from what was needed for the urban defence. A consistent supply of anti-tank missiles and man-portable air-defence systems will remain invaluable. But the force will also need loitering munitions to target Russian air defences and artillery, creating opportunities for Ukrainian helicopters to resupply isolated units. They will need protected mobility to move their troops safely to new defensive positions. They will need a considerable quantity of artillery ammunition.

Dr Jack Watling is senior research fellow for land warfare at the Royal United Services Institute (RUSI)