Economics of war

I would appreciate it if someone could enlighten me. The economics of this war do not make sense. According to past articles I’ve read (see previous posts on my blog), the oil in Iraq is estimated to only be worth $20B at full production. According to part articles I’ve read about what this war is going to cost, both in military terms and oil infrastructure rebuilding terms (see previous posts, again), I can’t figure how this war is going to cost us any less than $10B.

$10B profit, at an additional cost of:

a) the rest of the world hating us, increasing the likelyhood of terrorism against our nation => increased fear => increased “homeland security” spending and aa) decreased international investment in America.

b) continued investment into the middle east protecting the 51st state (my little joke).

c) many dead Americans and even more dead Iraqis on our hands.

d) more Americans ashamed to be American => reduced productivity

e) oil gets a 10-20 year additional lease on life

I would really appreciate a solid explanation. It doesn’t make sense…