Some new Ukrainian soldiers refuse to fire at the enemy. Others, according to commanders and fellow fighters, struggle to assemble weapons or to coordinate basic combat movements. A few have even walked away from their posts, abandoning the battlefield altogether.

While Ukraine presses on with its incursion into Russia’s Kursk region, its troops are still losing precious ground along the country’s eastern front — a grim erosion that military commanders blame in part on poorly trained recruits drawn from a recent mobilization drive, as well as Russia’s clear superiority in ammunition and air power.

“Some people don’t want to shoot. They see the enemy in the firing position in trenches but don’t open fire. … That is why our men are dying,” said a frustrated battalion commander in Ukraine’s 47th Brigade. “When they don’t use the weapon, they are ineffective.”

Commanders say the recruits have contributed to a string of territorial losses that enabled Russia’s army to advance, including near the city of Pokrovsk, a critical logistics hub. If it falls, the defeat would imperil Ukraine’s defenses and bring Russia closer to its stated aim of capturing the Donetsk region. Russian soldiers are now just 10 kilometers (6.2 miles) away.