It's interesting that so many reviewers are so excited by this episode because it has to do with warfare. I've always enjoyed the more intellectual types of science fiction and feel this is often the lowest common denominator. It's why I see the Star Wars original movies as more Western than science fiction. That aside, this particular offering, with the introduction of the Romulans and a battle of wits between the two Captains is very good. Kirk is probably at the best he has ever been. Because the two vessels are unknown to each other, they must do two things. They must analyze and they must react. We also have a pair of truly contrasting cultures. Throw in the Vulcan angle (a possible split of purposes back in the day) with Spock being seen as a potential traitor and it gets really interesting. The conclusion is well set up and I won't comment on it specifically, but really pulls the whole thing together. All the actors deliver nice performances. We don't mention the secondary people, like Mr. Sulu, often enough, but they are really significant in this episode.
Review of Balance of Terror
