The whole backstory of Stiles' bitterness towards the Romulans (which later transfers to Spock) doesn't really work if the war was supposed to have taken place a century before the episode.
He's clearly nowhere near old enough to have felt any of his family losses personally. It's like a present-day twentysomething hating Germans because he had relatives killed in action in World War I.
If they'd set the war only, say TWENTY years prior (as they later did in "The Wounded"), that might've made it work. Maybe Stiles could've lost a father when he was a teen or a child. That would've made his hatred make sense. As it stands, his bitterness is over the deaths of distant relatives he couldn't possibly have known.
You don't know any unReconstructed Southerners, do you?
Trust me, in some places the Civil War/War between the States/War of Northern Aggression is very much still remembered.
And of course and later shows and films confirmed that humans and Vulcans had been hanging around each other for a couple of centuries, which makes his abrupt suspicion of Spock as some type of Romulan spy that much more ridiculous.
There is a cut scene in the script (that may or may not have been filmed) where Commander Hanson warns of possible spies, noting that the BoP appeared to be based on stolen Federation technology.