Donald Rumsfeld
The United States was attacked on September 11, 2001 by al Qaeda terrorists who hijacked commercial airliners and crashed them in coordinated strikes into both towers of the World Trade Center in Lower Manhattan, New York City and the Pentagon in Washington, D.C. The fourth plane crashed into a field in Shanksville, Pennsylvania, and its target was likely a prominent building in Washington, D.C., most probably either the Capitol Building or the White House. Within three hours of the start of the first hijacking and two hours after American Airlines Flight 11 struck the World Trade Center, Rumsfeld raised the defense condition signaling of the United States offensive readiness to DEFCON 3, the highest it had been since the Arab-Israeli war in 1973.
History of the Middle East
One of these Arab militants was a wealthy Saudi Arabian named Osama bin Laden. After fighting against the Soviets in Afghanistan in the 1980s, he formed the al-Qaida organization, which was responsible for the 1998 U.S. embassy bombings, the USS "Cole" bombing and the September 11, 2001 attacks on the United States. The September 11 attacks led the George W. Bush administration to invade Afghanistan in 2001 to overthrow the Taliban regime, which had been harbouring Bin Laden and al-Qaida. The United States and its allies described this operation as part of a global "War on Terror".