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.
Planning of the September 11 attacks
On September 11, 2001, 19 Arab-Muslim hijackers took control of four commercial aircraft and used them as suicide weapons in a series of four coordinated acts of terrorism to strike the World Trade Center in New York City, The Pentagon in Arlington County, Virginia, and an additional target in Washington, D.C. Two aircraft hit the World Trade Center while the third hit the Pentagon. A fourth plane never arrived at its target, crashing in a field in Pennsylvania after a passenger revolt. The intended target is believed to have been either the United States Capitol or the White House. As a result, 2,977 victims were killed, making it the deadliest terrorist attack on U.S. soil; also the deadliest foreign attack on U.S. soil, exceeding Japan's surprise attack on Pearl Harbor in Honolulu, Hawaii, on December 7, 1941, which killed 2,403 victims. It was carefully planned by al-Qaeda, who sent 19 terrorists to take over Boeing 757 and Boeing 767 aircraft, operated by American Airlines and United Airlines.