Colonize Mars or Invade Iraq?

I know which I'd have chosen! When I was a child I dreamed of the Earth-Mars shuttle and a colony on Mars.

Charles Stross, whose novel Accelerando is my current sf read, asks,

Yes, I'm asking you: what would you do with the cost of the Iraq war (take your pick: $513Bn or $6000Bn) in your budget? Colonise Mars? Solve our carbon emission problem and fix global warming? House half a billion people? Or something else ...?

(And what isn't going to happen now, because we pissed it all away on the desert sands?)

HT: BoingBoing