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.
Richard A. Clarke
Clarke was involved in supervising the investigation of Ramzi Yousef, one of the main perpetrators of the 1993 World Trade Center bombing, who had traveled to the United States on an Iraqi passport. Yousef is the nephew of Khalid Sheikh Mohammed, a senior al-Qaeda member. Many in the Clinton administration and the intelligence community believed Yousef's ties were evidence linking al-Qaeda's activities and the government of Iraq.