Romulus and Vulcan as Korea.

[Mr. Scott]

it would have been interesting to have seen a divided society being protected by the Federation, who preferred one side (the Vulcans) against the Romulans (who could have been protected by another force.

The Planets are very close to each other but both sides have a cold peace, The Federation and the Vulcans on one side of the line and the Romulans (and say the Cardassians are a superior) guarding the other line.

I think it would be interesting.

 

[T'Girl]

Or a home world and a break-away colony, maybe less Korea and more like present day China and Taiwan.

 

[Reanok]

Former Star Trek book Editor Margaret Clark mentioned in an Interview that analogy of The Romulan Praetor when it came to the events leading to the Earth/Romulan wars in the Enterprise novels. The post nemesis TNG& Titan novels have dealt with a split In Romulan society and the tensions within the Romulan empire and split off colony worlds signing a treaty with the Federation.Also Vulcan is mentioned in the books with Ambassador Spock trying to reunite Vulcan & Romulas.

 

[diankra]

An interesting idea, but (to state the obvious) Vulcan (or rather Spock) and the Romulans were created a bit apart, so it's unlikely it occurred to anyone at the time.
If they'd wanted to have a more prominent 'cold war' ongoing background than TOS really did, then the Korean comparison would have been a very good approach.