Karate, Kung fu, tae Kwon do, tang so do, kenpo, etc... all pretty much useless in real hand to hand combat. Tbh, wrestling is a great way to defend self, subdue an attacker. If you've ever had any boxing experience and have learned how it feels to be hit in the face and know some basics of footwork and punching, thats about as good as its gonna get for your average guy, military or not.
Experience grappling and striking, boxing/wrestling, will get you past most untrained people. Now, all bets are off if you happen to run into a guy who loves fighting, a guy who's been in dozens or even hundreds of street fights, same for just about any level of professional fighter. They'll clean your clock. All the martial arts are for 9 year olds to collect trophies and different colored belts. It really is child's play, but its a good start for kids to learn competition, discipline etc...
Your average karate sensei (otherwise unemployed, 30 year old adolescent) is a joke. A lot of them give off strong pedo vibes. Fleecing single moms out of membership dues so they have a place to leave their kid for a few hours a day.
Seriously, a good and humorous look at these types is on the Instagram page McDojo life. Not all but most are living a fantasy. The akido masters who throw a dozen opponents with a twist of the wrist, channeling their "chi" are only slightly less pathetic than the losers who actually pay to fall all over the mat. Its bizarre, a weird form of social contagion.