war is a small minded big outcome game of BULLSHIT! this usually happens when an american president is owed money by a leader of another country. the man won't pay up, so the president then proceeds to frame the middle east for a series of attacks(aka 9/11), generating support from the american citizens. if the self creating attacks aren't enough "proof" of "need" to go to war, there is what we call a draft.
George Bush: Bin Laden, you owe me a handful of money. pay up!
Bin Laden: No George Bush. Spawn a war in your own country, and i guarantee you'll generate more money than you can shake a stick at!