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.
Fred Burton (security expert)
While with the DSS, Burton was appointed by Washington to assist in the investigation of the assassination of Israeli Prime Minister Yitzhak Rabin. He also investigated the killing of Rabbi Meir Kahane; the al Qaeda New York City bombing plots before the September 11 attacks; and the Libyan-backed terrorist attacks against diplomats in Sana'a and Khartoum. He was involved in the arrest of Ramzi Yousef, the mastermind of the first World Trade Center bombing in 1993.