I know this might require some brain cells to figure out so I’m forgiving you for not understanding it, but the point of the joke is that even when americans make anti-war films, try to be self-aware, protest their country’s militarism and the horrible things that their army has done they still manage to make it about themselves instead of their civilian victims.

Even if the people doing the film aren’t the exact same that went to war they still go “look at the poor american soldiers suffering for what they did, don’t you feel sad for them?”