special military troops.
Synonyms: elite troops, rapid deployment troops, special troops, storm troops.
(Believe it or not, it has nothing to do with crack
cocaine. This term has been used since before jesus was born. Sun Tzu, the man who wrote "The Art of War" well over 2000 years ago used this term in his writings. Of course, back then,
people who used the coca plant didn't call it
crack.)
This term was simply based on the analogy that employing these troops could create "cracks" in an enemy's military structure or strategy.