All the above are appropriate, some very moving. What about "Eve of Destruction" from the late sixties, sung by Barry McGuire (?). I recall it was banned by the BBC for a while. The first line was "The Eastern world, it is expoldin'..", then later it went on to say "..you're old enough to kill, but not for votin'..."

John Lennon's "Imagine" is another good one.

On the lighter side, there is Tom Paxton's "Lyndon Johnstone told the nation", "Willing Conscript", What did you learn in school today, all on his "Aint that News" album.

And more recently, "There's a better way" (Niall Toner Band)