Soviet military joke

INFO:
A Soviet soldier and an officer are chilling together at the base. The soldier goes to the officer and says, “Comrade/captain! Can you tell me why is your shirt red?” The captain says, “Well, comrade/private, if we go into battle and I’m shot, I don’t want you to know that I’m bleeding out and I want you to keep on fighting.” And the private goes, “Oh, okay, that makes so much sense! That must also be why your boxers are yellow.”

BACKGROUND:
He was told this joke by his Russian friend, about ten years ago. They were just talking about military stuff, maybe playing a video game together, when unprompted, the informant’s friend shared the joke. The informant still thinks the joke is funny, but

CONTEXT:
I spoke to my informant during an on-campus event.

ANALYSIS:
Clearly, there are some attitudes about the Soviet military, and perhaps the entire Soviet political structure, being expressed in this joke. It takes the idea of the “cowardly officer” but expresses it in the faux-egalitarian framework of the Communist regime. Even though I don’t completely understand the joke in and of itself, I can still feel the upwards-directed anger within the officer/private confrontation.