In STV: TFF, it was revealed that Nimbus III was established as a Planet of Galactic Peace between the Federation, the Klingon Empire, and the Romulan Star Empire. And based on the date of its establishment, that places it during TOS S2. But considering the extremely limited contact between the Federation and the Romulan Star Empire, wasn’t that a little quick for diplomatic channels between both sides to open? Between TOS and TAS, the Romulans only made 5 appearances (I’m not counting “The Time Trap” here.) “Balance of Terror” (2266) “The Deadly Years” (2267) “The Enterprise Incident” (2268) “The Survivor” (2269) “The Practical Joker” (2270) I get that Nimbus III being a Planet of Galactic Peace, and was established in the aftermath of “Errand of Mercy”. But how did the Federation manage to reach out to the Romulans, considering that the Romulans had a habit of surrounding the USS Enterprise on a yearly basis and were in a combative state? The Federation only had one encounter – maybe two – with them since the Earth-Romulan War and in the run up to the founding of Nimbus III, and “Balance of Terror” makes it clear that both sides had no contact with each other until this episode. Were the Klingons and Romulans on speaking terms by this point, since there was a technological exchange that is seen in “The Enterprise Incident” and continued in TSFS when the Klingon BoP uses a cloak? And therefore, the Klingons invited the Romulans to the establishment of Nimbus III? Or were there other encounters between the Federation and the Romulans during that time that we are unaware of that contributed to the Romulans being willing to join the Federation and the Klingons on Nimbus III?