Conceived by Gene Coon after the 1965 Watts Riots in Los Angeles (before being rejected for the first season and resurrected for the third), this ship-based racism episode can seem a bit heavy handed today with its allegory but has some interesting elements that make it worth a viewing.
With a teleplay by Oliver Crawford (cowriter of "The Galileo Seven"), the seemingly simplistic idea of racism is deceptively layered. Budget cuts require that the two warring factions be condensed to two representatives, but they are more than the oppressed and the oppressor: Bele (Frank Gorshin) sees himself as a policeman and an aristocrat, a precursor to Odo. He attempts to reason with Kirk, Spock, and Starfleet Command, ignoring the "little people". Lokai (Lou Antonio), on the other hand, is the populist and attempts to rally the junior officers to his cause, seeing them as his peers. And yet both their arguments distill down to idea that having white on a certain side of their faces and black on the other side (opposite for each) makes them right. Is the make-up silly? Sure. But the genius in the idea lies in the characters' reaction to it. Lokai and Bele assume it's so obvious that their pigmentation makes them superior that they are stunned when Kirk, Spock, and everyone else don't immediately understand this. It's a sort of perspective that isn't unique to racism, with mistaken assumptions spilling into class, politics, and religion as well. And what's really bold about the episode is that neither the oppressed nor the oppressor is portrayed as "the good guy"; in the end, their hatred is akin to their skin: mirrored reflections of each other that become indistinguishable to the crew of the Enterprise... and ostensibly, the viewer. (It's the Jonathan Swift thing, creating a situation that allows the audience to look in from the outside and see the absurdity for what it is).
And yet all the same, the episode never attempts to dig deep into its ideas or aspects, content to merely scratch the surface. (In fact, the director had to add some padding at the end to avoid running short). Worse yet, the superfluous Batman-like directing creates a frivolous feel that undermines some of the drama and can be downright distracting, even in a gem of a scene where Kirk and his officers set a countdown for the ship to self destruct (a foreshadowing that finally pays off 15 years later in the third feature film).
With its talented authors, it's no surprise that "Battlefield" has something interesting to say, and it's nice that like several of the early episodes of the series ("The Man Trap", "Where No Man Has Gone Before" and "Charlie X"), the writers don't feel it necessary to end with a joke or a laugh; but in the end, the episode doesn't know how to say what it's getting at.
There's actually a surprising amount for CBS Digital to do here. In addition to new shots of the Enterprise, we get an extended shuttlecraft sequence (originally footage lifted from "The Galileo Seven", but replaced here with new shots of a shuttlecraft appropriately bearing Starbase 4's markings) and two planets (originally a yellow tinted version of the "Operation: Annihilate" planet and a reuse of "The Deadly Years" planet, but upgraded here to two more impressive, original spheres with the appropriate damage as indicated by the dialogue).
Unfortunately, the digital team is unable to do anything about the most ridiculous budget saving concept the original series ever came up: Bele's invisible ship which deposits its pilot onto the Enterprise and disintegrates. (What is this, Wonder Woman?) With the dialogue set in stone, it's impossible to replace it with anything else.