I can't believe no ones mentioned the other great Eric Bogle song, The Green Fields of France.
Finbar Fury made me cry singing it (twice), but strangely enough Bogle himself didn't.

I just quote the last verse:

And I can't help but wonder, young Willie McBride,
Do all those who lie here know why they died?
Did you really believe them when they told you "The Cause?"
Did you really believe that this war would end wars?
Well the suffering, the sorrow, the glory, the shame
The killing, the dying, it was all done in vain,
For Willie McBride, it all happened again,
And again, and again, and again, and again.