There is much symbolism associated with death and the Ace of Spades playing card and the Grim Reaper are two such symbols. Being used together is merely redundant. A person wearing the Ace of Spades embroidered patch is suggesting to the knowledgeable viewer that they will fight to the death whenever provoked.
What do we know about the ace of spades in Vietnam? Did it truly terrify the Viet Cong and North Vietnamese Army regulars and leave them trembling in fear? Did American military units all throughout Vietnam use it? The answers would seem to be a resounding "no." In fact, some intelligence studies indicate that the Vietnamese had no concept that the ace of spades represented death.
Where did the concept that the ace of spades was a bad omen originate? Apparently in the distant past. The history of the ace of spades goes all the way back to the age of pirates. The single spot on the card could put you "on the spot" or in danger. The origin of this expression goes back to 18th-century pirates whose back-up symbol for intimidation (after the skull and crossbones) was the dreaded ace of spades with its single black spot. This card was intentionally shown to a traitor or informer as warning that his life was in danger. Anyone sent an ace of spades was "on the spot."
