Character Analysis
Kruge is played by Christopher Lloyd, everyone's favorite bug-eyed purveyor of odd yet likeable characters. But this Klingon commander is no Dr. Emmett Brown. There's not a Delorean in sight.
And while he may share Uncle Fester's affinity for weapons, that's where the similarities stop. Kruge's most redeeming quality is that you love to hate him…because he's bad to his core.
A Moustache Well Twisted
Kruge's 100% the antagonist of The Search for Spock. But let's make something clear: being an antagonist doesn't necessarily make you a bad guy. To be an antagonist, you simply have to be in conflict with the protagonist—which means that plenty of antagonists can, in fact, be good guys (see Sam Gerard from The Fugitive and Jack Valentine from Lord of War for examples).
But Kruge ain't this type of antagonist. Not even close. For starters, he dresses like a militant Dethklok groupie and clearly bought his dog-jackel-thing from Mordor Pets and Supplies.
But villainy is more than skin deep, and his actions clue us in to his murderous brand of evil.
We're introduced to this characterization in his first scene. After Valkris uploads the Genesis data to Kruge's Bird-of-Prey, she accidentally lets it slip that she's seen the data:
VALKRIS [in Klingon]: Transmission complete. You will find it useful.
KRUGE [in Klingon]: Then you have seen it.
VALKRIS [in Klingon]: I have, my lord.
KRUGE [in Klingon]: Unfortunate.
VALKRIS [in Klingon]: Understood.
Kruge then destroys the ship she's on. (Excessive.) And her last words?
VALKRIS: Success, my lord, and my love.
Yeah, the guy blew up his own sweetie-pie just because she took a peek at his evil plan. Later, he'll kill his gunner for accidentally blowing up the Grissom…despite the gunner following orders and hitting the engines as Kruge specified. Kruge is real big on explosions.
But Kruge's most villainous moment comes after the Enterprise and the Bird-of-Prey battle each other to a stalemate. Kirk tries to strong-arm Kruge into surrendering, but Kruge sees through Kirk's bluff. He orders Kirk to surrender…or he'll kill one of three prisoners he has below, David, Saavik, or Spock:
KURGE: I meant what I said. And now to show that my intentions are sincere, I shall kill one of the prisoners.
KIRK: Wait a minute! Give me a chance to talk—
KURGE [in Klingon]: Kill one of them. I don't care which.
Ultimately, David's killed in a scuffle with his Klingon captors. What is really heinous about this scene is that Kruge didn't even need to kill one. He had the upper hand (and knew it), and Kirk had no choice but to surrender. But to demonstrate his power, Kruge got all murder-y.
What a dude.
Even with his deep, abiding love for dynamiting things and getting his murder on, Kruge still wouldn't be a true antagonist unless he had a quality that was fundamentally opposing to our protagonist, one James T. Kirk. Lucky for us—and unlucky for any character crossing his path—he does.
Kirk's mission isn't for the betterment of himself or his own position in the world. He goes on this mission because, as he says to Morrow, any chance to save Spock and McCoy is a chance worth taking. In his pursuit, he sacrifices his career, his ship, and his son to do what he sees as right.
Kruge, on the other hand, quests for Genesis because it will be the ultimate weapon. (Try saying "ultimate weapon" without following it with a "mwahaha." It's impossible.)
Genesis will give him the power to destroy his opponents and achieve his goals. And it's this conflict between selfless actions and selfish ones where the true conflict between the two lies.
A Word about Klingons
Klingons in the Original Series were your typical bad-guy-of-the-week villains. Think your Decepticons, your Puddies, your Cobra Command. Adam Roberts describes them as "brutish, devious, dangerous, and murderous, the very embodiment of a racist demonization of the oriental other." (Source)
But Roberts also notes that Klingons evolved as Trek continued, and by The Next Generation, the alien race was "treated in a more sympathetic light."
Kruge exists between the Klingons of the Original Series and The Next Generation. He's brutish, dangerous, and murderous …but the movie makes it clear that he doesn't represent all Klingons. As Kruge points out:
KRUGE: Even as our emissaries negotiate for peace with the Federation, we will act for the preservation of our race. We will seize the secret of this weapon, the secret of ultimate power.
The line demonstrates the change taking place within Klingon society, and how the series is planning to handle the aliens in the future. That Klingon emissaries are negotiating for peace with the Federation suggests a large population of peace-seeking Klingons exist in the universe. They just don't appear in the film.
This new treatment of the Klingons is in keeping with Star Trek's overarching theme of peace and cooperation between different peoples and culture. The line also deeps our understanding of Kruge as the antagonist…because he's very much not about peace and cooperation between peoples and cultures.
And in case you wanted to put yet another check mark on the "Kruge Is A Monster" column? Dude's motivation to preserve his race isn't only evil and dangerous because it poses a threat to the Enterprise and its crew; it also poses a threat to the wishes and desires of these peace-seeking Klingons.
Think Kruge won't turn the Genesis device against his fellow Klingons if they disagree with his politics? Do we have to remind you what he did to his girlfriend? (RIP, Valkris.)
Thankfully, Admiral Kirk puts a stop to that threat when he kicks the Klingon commander into a lava pit—the preferred method to dispatch final bosses in movies and video games from time immemorial.
Game over, man. Game. over.
Kruge's Timeline