Comrade Buc is the opposite of Jun Do: he's got family (and lots of it), he comes from a long line of distinguished people, he has a high social standing, and he seems not to mind the blood-curdling realities of life in North Korea. In fact, he seems to be doing just fine the way things are.
In a playful moment on the plane to Texas, Dr. Song implores Comrade Buc to "apply" his seat belt, since he is a young man and has a family to think of. This seems to be an appropriate metaphor for Buc's proceedings throughout the work. He's a careful man, prepared with a plan for the worst possible situation.
We get a hint of this as the guys return from their unsuccessful trip to the U.S. Buc tells Jun Do not to worry: "'... if I thought someone on this plane was headed to the camps,' he added, turning to Jun Do to make sure he was being heard, 'I'd smash his head on these rocks myself'" (163). That may not be reassuring to most people, but Buc doesn't go in for suffering, and he won't let his loved ones go that way, either.
As a good and careful husband and father, Buc devises a plan for his family has even more forethought. His hording of tainted peaches and his willingness to distribute them among his family members at the slightest sign of trouble shows us that Buc is an incredibly adaptable guy, one who accepts his high status for the precarious situation that it is.
Despite his weirdness about the peaches, Buc seems like a happy-go-lucky guy. He's very willing to extend friendship to Impostor Ga—perhaps because he killed his least favorite Commander—and he's also able to forgive Ga for TMI on the defection situation.
He's also in a unique position in the novel: he knows both Jun Do and Imposter Ga. As such, he's in an even more dangerous situation. And he's problematic for Jun Do/Ga. Impostor Ga knows this, and nearly loses his nerve when he sees Buc on he first day back at the office:
Seeing Comrade Buc—his smile, his thumbs-up—had opened a void in Commander Ga between the person he used to be and the person he'd become. Comrade Buc was the only person who existed on both sides of Commander Ga's void...Now Ga felt rattled. He felt newly aware that he wasn't invincible, that it wasn't destiny in control of him but danger. (225)
If rekindling his friendship with Buc is difficult and dangerous for Ga, it's really downright disastrous for Buc. His wife is right to resent Ga, because he's poking at a hornet's nest, and all of them are about to get stung. No matter what safeguards Ga thinks he's putting in place—including giving up his dream of being with Sun Moon in America—he can't predict what associations the regime will make when it comes time to exact revenge.
In fact, the association is merely situational. Buc is helping at the airport; therefore, he must be complicit. It turns out that after all his careful behavior and planning, Buc's family has to deploy the peaches, anyway.
We remember Jun Do stating his bewilderment upon entering the prison camp: "I was a model citizen... a hero of the state" (175). When Buc faces the possibility of implication in Sun Moon's defection plot, he tries to plead with the Dear Leader in the same way, as if justice were the first thing on the dictator's mind: "It's me, your closest comrade. Who gets your cognac from France and your sea urchin from Hokkaido? Who has procured for you every brand of cigarette in the world? I'm loyal. I have a family" (437-438).
Buc pulls out all the stops here, but as Jun Do has already learned, you can never do enough in a state that knows no limits. As Commander Park puts it "... the amount of pain that will come of this, it'll be too much for a single man to bear" (437). Well, that's reassuring. While Buc's eyes have been opened, it's too late to save himself or his children.
Though speaking the truth and hoping for justice doesn't work out so well for him the first time, Comrade Buc decides to have another crack at it. This time, though, his words are meant to wound. After the Interrogator forcibly takes his wedding ring from him, Buc lets loose all the ugliness he's been holding inside:
"Eleven years I procured for those prisons. The uniforms come in children's sizes, you know. I've ordered thousands of them. They even make a half-sized pickax... For eleven years, the prison doctors order no bandages and the cooks ask for no ingredients... But they must have transfusion bags right away. They must have bullets and barbed wire tomorrow!" (240)
But like Impostor Ga's revelation that Duc Dan had been locked away in Prison 33, the horror of reality slides off the back of the interrogators. They choose not to believe that a good and loyal servant could sink so low—otherwise, what would be the point in another day?