A student at the Special Operations Combat Medic Course and School applies a tourniquet to a simulated wound during a casualty scenario at Fort Bragg, North Carolina Feb. 16, 2023.Petty Officer 2nd Class Russell Lindsey/US NavyLessons from Ukraine are reshaping battlefield medicine as prolonged evacuations become more likely.US special operations medics are graded on when and how they safely remove tourniquets from casualties.Tourniquets save li…