What could we pay for with the $$$ poured into the war in Iraq? Charlie Stross makes some calculations:

Going by Stiglitz’s indirect estimates, the picture is even more ludicrous; for $3Tn, assuming a crew of four per expedition, $20Bn per flight, and a basic $450 start-up price, you could send 510 astronauts to Mars. That’s not a Mars exploration program, that’s a battalion! It’s a small colony!

Seriously, war is such a bad idea. Even though we may argue about the necessity of a Mars trip, investing the money in renewable energy (or even nuclear power plants), global education, water resources etc. would be A. LOT. BETTER. THAN. WAR.