I've heard that in the Army in basic training they teach you unarmed fighting techniques and they teach you quick ways to kill with your bare hands. Im not sure if this is true but I heard that upon completing basic, or after you've been in the Army long enough and have learned enough, that you're about as good as the average black belt in a fight.
Unless the individual soldier or marine seeks out specific training in unarmed combatives or other martial arts they will not be well trained. I have had the opportunity to assist with the instruction of one of the SF groups (my instructor was the contract instructor for them), and they were for the most part just as inexperienced as most of the civilians I have trained. Far better "combat mentality" that most civilians, heck, better than me, most of them had seen combat, but their unarmed or knife/stick/machete skillsets (on average) weren't anything to speak of.