Re: Imagine the TOS Starfleet
We know that the authority the Enterprise answers to is a "combined service"
I think Kirk was referring to Starfleet being a combination of the Air Force, Navy, Army, Marines and Coast Guard.
I always got the feeling when watching TOS that the Federation itself was much younger than the spin-offs said.
"Just give me two seconds, alright, you mad bastard!" - Montgomery Scott, Star Trek Into Darkness