Like it or not, the United States is the leader of the free world. We have maintained that position for a long time. IMO, a good leader is someone who does what they think is the right direction for the people. Bush tried to get the support of countries such as Germany and France. He could have gone to war before he did. They refused to come along with us. At some point, a leader has to lead and make tough decisions.
The policy of containment in the Cold War has cost us billions of dollars throughout the years. We were engaged in a staredown contest with the Soviet Union that spread fear, misinformation and general paranoia amongst the population. We were much better when the Soviet Union collapsed when Reagan forced the issue.
The policy of preemptive strike, IMO, came about partly as a response to the criticism from the left that Bush could have done more to prevent 9/11. Now, we hit before they get a chance to hit us. I feel much safer in that situation, rather than play the reactionary role. Who knows how many Americans will die if the bastards hit us again? That's not a risk I want to take.