During the Falklands the Ghurkas went out each night and decapitated a few solders in their foxholes. Pretty soon the Argentine soldiers flat out refused to do outpost duty at night, and the Brits could move about at will in the dark.
Not quite. The Argentines own propaganda bit them in the a$$. They had portrayed the Gurkhas serving in the British Army as being savage cannibals, in hopes that the Argie conscript troops would eliminate them without mercy. Instead they were terrified at the prospect of close-quarters combat with the Gurkhas, and when the Ghurkhas of the 1st Battalion of the 7th Gurkha Rifles finally moved in on the Argentine positions at , the young Argentine troops surrendered. Smart move.
One Gurkha was killed during the Falklands, a rifleman whose field spade set off an unexploded hand hrenade while digging a fighting position after the fighting was over. The Argentines lost 648 of their men.
I think that you are mistaken. To my knowledge— reading the response of a British officer serving with the Gurkhas in the Falklands War—the Gurkhas didn’t get to kill anyone. The Argentine conscripts fled in panic at the very rumor of their approach.