The introduction of night vision technology during the Vietnam War transformed how u.s. military men and their communist enemies fought at night. The starlight scope’s seemingly miraculous light-amplifying powers made hitherto unseen targets easier to see. And as sole possessor of this new technology, American soldiers had a profound tactical advantage operating at night. But they also paid a price for this new edge. Burdened by the scope’s weight, untested technology, and extreme secrecy, these servicemen suffered. They endured physical, psychological, and emotional stress unforeseen by the military leaders who pushed for the scope’s development during the Cold War. The new rifle-mounted scope figuratively transformed night into day, and, paradoxically, made it harder for many American soldiers to pull the trigger.