You are laboring under a simplistic view of the world.
First off, there was a horrific event on Sept 11, 2001 now known as 9/11. This was engineered by an organization run by a fellow called bin Laden, who was living in Afghanistan under the protection of the Taliban.
Now get a map of the region and look at how the military is supposed to get to Afghanistan. If you were the President, how would you get your armies there, over which neighboring nation ... fly the planes, have the aircraft carriers, cruise missiles ... what nation get permission to go over?
Well Pakistan was the answer.
Moving on, President Bush did a lot of good stuff, but he also acted on some incredibly ignorant guidance from some people. There is this ideology that says Democracy is the best form of government and in the best interests of America to have all over the world.
Ok look at the Middle East ... there are millions of people who hate Israel and want to destroy Israel, then after Israel gone, they feel the same way about America.
They were in nations taht were pro peace with Israel and America. Then the USA pressured the nations to go Democratic, so now the people who want to destroy Israel and America have won the elections and those nations are well on the road to carrying out that Democratic will.
Do you think that was a good idea?