Having never served in the armed forces, you don't know that most Specialists (E-4) are about 20 years old. The man wearing the E-4 rank looks like he should be a Staff Sergeant at least (E-6). Though it's possible for a man in his late 30's to have such a low enlisted rank, it's very rare.
He's an actor.
And you're very gullible.
I was in for 21 years and retired in 1997. You?
As for his age, he could be a Guardsman or a Reservist or simply someone who decided to join later in life rather than straight out of high school.
Your zeal to prove me wrong and claim this is all a ruse is interesting. Why are you so anxious? You can't see the possibility it could be one of a dozen or more times the show tried this and this was the best of the lot? Are you afraid you'd wimp out and run or be caught saying "Yeah! **** that Jihadist, donkey-******* asshole! Get a rope!"?
Or are you defending your "girlfriend", Goosey? Planning on mutual handjobs later?