But, I mean, a 'war' should at least have the two sides be at odds.
Big Boss wasn't opposed to Zero until the end of Peace Walker, maybe disliked him for a year, and the two had reconciled their differences by the time he woke up. So they were maybe pitted against each-other for a year, and never actually did any fighting.
Big Boss left Zero over LET, and Big Boss wasn't aware of Zero's visit, by the time he came to Zero was already braindead and hidden away, with his organization being run by proxy, misusing the legacy. Ocelot, Big Boss, and EVa ended up going to war with Zero's phantom. (sorry 'bout that lol)
I got the impression that it was a shadow war. Not one fought by armies on a battlefield, but still just as heated as a hot war . It was a war fought by schemes and espionage. Hence EVA and Ocelot plotting to kill Para Medic and Sigint.
Yeah that all happens. The stuff with Zero in V was information for the player to contextualize his character, and how his ideals could become corrupted and lead to the problems it did. Otherwise he was a wacky James Bond fan with a silly movie buff doctor and wacky black guy black guy guy. I feel that, between PW and V, we have a proper bridge between 3 and 4. This game fixes 4's problems, which sucks because 4 shouldn't have had the problems it did in the first place, but at least I don't feel like half of 4's story is un-deserved nonsense (even if it's in hindsight)
And like...we still might get more out of V. there could be DLC plans...Camp Omega, Kingdom of Flies, New York even? I feel like if we get to december and we haven't heard anything, though, it might not be happening. (But we're still early. There's still cruises to ruse)