Article 51 of the Charter of the United Nations, which was implemented immediatley following WWII. The Germans used the strategy of preemptive war on its neighbours, and it was this article that has been in place for almost 60 years now, that tried to disuade powers from pre emptive attacks.
http://www.nato.int/docu/basictxt/bt-un51.htm
The Terrorist attacks now gave the US an excuse for ripping that page out of international law. The US has told its citizens you will not be safe unless pre-emptive action is taken to thwart terrorists and terrorist states. The citizens allowed this, and the American Empire continues.
[quote:03863]Of course the people don't want war. But after all, it's the leaders of the country who determine the policy, and it's always a simple matter to drag the people along whether it's a democracy, a fascist dictatorship, or a parliament, or a communist dictatorship. Voice or no voice, the people can always be brought to the bidding of the leaders. That is easy. All you have to do is tell them they are being attacked, and denounce the pacifists for lack of patriotism, and exposing the country to greater danger."
-- Herman Goering at the Nuremberg trials [/quote:03863]