After 225 days stuck in a front-line foxhole, the Ukrainian infantryman's muscles were so weak he could barely walk. His commanders had tried five times to swap him with another soldier - but they could never reach him. Rotating soldiers on the front line in eastern Ukraine is extremely difficult because of the constant threat of drones.

This area near Kostyantynivka is currently one of the most dangerous hotspots, and the Ukrainian military admits that Russian forces have reached its outskirts. Known as Kenya, the infantryman took two days to walk 11km (6.8 miles) to get back to his brigade, avoiding mines and hiding from drones.

The 93rd brigade has the job of defending Kostyantynivka and its surrounding towns and villages from Russia's advance. If this highly strategic city falls, Moscow will be able to push towards the last remaining Ukrainian strongholds in the Donbas region – Kramatorsk and Sloviansk – from the north, east, and south.

Vladimir Putin sees the capture of the Donbas as Russia's priority goal, and Ukrainian intelligence indicates that he wants it done this year. President Volodymyr Zelensky believes the Kremlin is planning another major offensive in the summer, but Russia's campaign has lately become bogged down in the region.

Kenya's task was to maintain his position and listen for any movement outside. Most fighting was done by drones, which have transformed how wars are fought. With machines increasingly replacing humans, the role of troops has become crucial in seizing or defending land.

Speed has become more important than armor to survive in the kill zone dominated by drones that hunt anything that moves. The drones cannot seize positions; boots on the ground are still essential for territorial control.

Life in the kill zone is harsh, with soldiers lacking basic necessities like water and food. Many recount their struggles with malnutrition and the psychological toll of constant risk.

As Ukraine prepares for potential Russian offensives, the resilience of these soldiers exemplifies the evolving nature of modern warfare, where technology and human endurance collide amidst the grim realities of combat.