His unit decimated by Ukrainian fire, the last surviving soldier in a Russian assault took cover in a shallow crater while Ukrainians shouted at him to surrender. As he lifted two grenades in the air, a Ukrainian drone swept in from above and exploded.

Soon, the smoke cleared, a surveillance drone overhead showed, revealing the Russian soldier’s corpse. That day’s attack, just north of the destroyed city of Avdiivka, was repelled. But the Ukrainians were under no illusions: There would be many more.

“They come in waves,” said Lt. Oleksandr Shyrshyn, 29, the deputy battalion commander in the 47th Mechanized Brigade. “And they do not stop.”

As the war enters its third year, Ukrainians find themselves outmanned and outgunned. After dominating the fighting in the first year and battling mostly to a standstill in the second, they have relinquished the momentum to Russia. Now they are digging in and fighting to hold on.

Mortar crews need to ration artillery shells. Troops are being rotated from units in the rear to join undermanned infantry units at the front, and there are shortages of critical supplies needed to repair and maintain Ukraine’s armored vehicles.