Well, it can buy you a nice new Trident missile nuclear deterrent system. Or it can future proof Britain against CO2 emissions and massively reduce our contribution to climate change.
So what is our Government likely to do. Hmmm, let's think about that for a moment.
Option 1: a deterrent that, in this world of terrorism, deters pretty much no one (what nation state offers a military threat worthy of a nuclear strike? The US maybe? Now there's a conspiracy theory for you!).
But then, is being a deterrent really what Trident is all about? Or is it your typical macho World Leader's equivalent of buying a big, fast, flash (and probably red) car? It's just toys for boys: something that lets you pose in front of your mates, and which impresses the girls (you can just see Clarkson interviewing Blair on Top Gear).
Option 2: spend the money to help fight the biggest threat our country, and the whole World, has ever faced. And maybe actually do something about it? It's an obvious choice really...
(see the article in Saturday's Guardian)