On September 11, 2001 a series of four coordinated terrorist attacks by the Islamic terrorist group Al-Qaeda on the United States. They hit the World Trade Center and the attacks killed and injured thousands of people and caused billions of dollars worth of property and infrastructure damage.
United States President George W. Bush declared a "War on Terror" which also saw the United States Army invade Afghanistan, beginning the War in Afghanistan. This led to American forces installing a new government and attempting to stabilize the region, while clashing with the forces of the terrorist organizations Al-Qaeda and the Taliban. Meanwhile, they also invaded Iraq and ousted their leader, Saddam Hussein, beginning the Iraq War.