what cause?

I’ve got a friend he’s a pure-bred killing machine
He say’s he’s waiting his whole life for this.
I knew him well when he was seventeen.
Now he’s a man he’ll be dead by Christmas
And so, everybody’s going to war
But we don’t know what we’re fighting for
Don’t tell me it’s a worth cause
No cause could be so worthy.
If love is a drug, I guess we’re all sober
If hope is a song, then I guess it’s all over
How to have faith, when faith is crime
I don’t want to die
If god’s on our side, then god is a joker
Running out through the door and straight to sky
I don’t want to die

lovely nerina pallot, everybody's gone to war