The US Army's Modern Army Combatives is a pretty badass system used to train our soldiers effective hand-to-hand combat. They employ a ton of BJJ/submission grappling techniques and principles and use competitions as a means of motivating soldiers to train. I saw a TV show about it once, so I'm kind of an expert on the subject.
Modern Army Combatives has four levels, starting from Basic, which is grappling starting from knees, all the way up to Advanced, which is full-blown MMA style fighting. And, they do it all in fashionable camo fatigue gis.
Check out Ranger Up's kickass highlight of the 2011 US Combatives Championship, held in the last week of July at Fort Hood, TX. These soldiers go for broke. Great competition.