i went to military school for two years, and they have an organization there called swampfox.
it was created in 1963 by spec ops soldiers returning from vietnam, the main goal was to teach future soldiers how to combat gurilla warfare.
today, it serves as a ‘prep school’ for those interested primarily in branching combat arms in the army, specificly infantry/ranger/special forces.
however, we also have foxes in the naval and air force branches as well.
infact, one of guys in this video is a pre-seal training (i don’t know the offical designation for it)
the cycle is two weeks long, 24/7 unless you are in academic class. it culminates with a timed 20kilometer forced ruck run in full gear. if you pass the cycle, you are then granted access to training normally unavailable to cadets. it focuses on rappelling, weapons familiarization, combatives, and other small-unit tactics
thought some of T-Nation might be interested