Ah, the proverbial military security phrase, usually preceded by "Halt!" Movies and books have shown simple ways to get past guards: throwing gravel, pebbles, rocks. Making the guard jump, look, even go investigate. In a way, movies and books were telling us a bit about the PTSD a soldier can get. Hypervigilance — jumping at noises, seeing shadows.
It doesn't take declared war — or military action of whatever name politics calls it — to create PTSD. Just trauma, being placed in a situation (often repeatedly, but sometimes just once) where showing extreme vigilance was a survival mechanism. It means being hyperaware of sights, sounds, smells. And it means assuming, and mentally preparing for, the worst-case scenario.
