A soldier wounded in Korea in 1951 had better survival odds than soldiers wounded in World War II despite heavier casualties and harsher conditions. The difference was time. Mobile Army Surgical Hospitals brought surgeons closer to the front lines, and helicopters brought casualties to them faster. That innovation evolved into today's Forward Surgical Teams, 20-person units that can set up a functioning operating room in an hour and perform life-saving surgery within kilometers of active combat.