Entering and leaving trenches in Ukraine can be highly dangerous.

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Ukraine's front lines are unforgivingly brutal, and soldiers are often injured or killed just rotating in and out of their own trench systems, a Western commander leading a training program for Ukrainian soldiers told Business Insider."We hear that Ukrainian forces take quite a few casualties infiltrating and exfiltrating out of their own trench systems because the front has been static for a very long time," said Brigadier Atle Molde, the commander of Task Force Legio, a Norway-led multinational effort to train Ukrainian soldiers on NATO soil.Swarms of drones overhead gather intelligence and attack, making any movement a risk. Ukrainian commanders have described troop rotations as among the most vulnerable moments for front-line soldiers.The drone-saturated area around the front lines is often described as a "kill zone." A Ukrainian official previously told Business Insider that just getting to front-line positions can take days and that it is the most dangerous part of the mission in many cases.Troop rotation, resupply, and relocation also present tremendous risks.That danger is why the Western training program puts particular emphasis on moving in and out of trench systems. At Camp Jomsborg, a purpose-built training site in eastern Poland, "it's all about saving lives," Molde said.