Along with downloading the song for free, why not support the anti-war efforts of "Peace Not War" by buying their CD, which has this very Billy Bragg song on it? It is an excellent CD, and the money goes to fund anti-war organizations, like the UK's Stop the War Coalition.

http://www.stopwar.org.uk/

If you scroll down, on the far left is a link that says "Peace Not War CD".

And you can go here, and read Billy's own words about the song:

http://www.peace-not-war.org/Statements/