Notice the Pol Pot line at the end, apart from referring to the leader of the Khmer Rouge (Pol Pot aka Saloth Sar aka Brother Number 1), hes also referring to the rampant use of drugs (pot in this case) among the US troops in Indochina.
And I think by subtlety rugbyLEAGUEfan means he doesn't just sing war is bad mkay, they're killing eachother mkay and so on, like almost everyone 'till then. He puts it in a completely sarcastic storyline. It doesn't attack the Khmer Rouge regime as much as it attacks you. Its subtle because when you listen to it at first, you think its just about some 'Merican dude leaving for a "holiday" in Cambodia, but on closer inspection its about all of us in the "1st world", how we are completely ignorant to suffering of Cambodia yet we're worrying about being snazzy and getting a stereo. The song is probably linked to their other song "When Ya Get Drafted".
But by subtlenes I still stick with "Kill the poor" because its completely from a rich guys perspective, who thinks if we kill the poor we will solve all of our problems.