After the fall of the Soviet Union the president of the U.S. declared a New World Order where the U.S.would take the lead in creating a unified and secure world.
New World Order
There was an emergence of terrorist groups who tried to use a fundamentalist interpretation of Islam to justify killing others. Of those groups was al-Qaeda and they carried out a terrorist attack on the U.S.
The Taliban refused to extradite Bin Laden to the U.S. so the U.S. congress authorized the use of force to capture him.
Saddam Husssein was connected to the September 11th terrorist and is stock pilling weapons of mass destruction.
The United States along with a few of its allied forces invaded Iraq which sparked the beginning of the Iraq War.
The United States eventually captured Osama bin Laden and killed him May 2nd 2011.