David Gergen has served in the administrations of Presidents Nixon, Ford, Reagan, and Clinton. He currently serves as editor-at-large at U.S. News & World Reportand is a professor of public service at Harvard's John F. Kennedy School of Government. He is the author of "Eyewitness to Power: The Essence of Leadership, Nixon to Clinton."

Last night, David Gergen spoke at the John F. Kennedy Library in Boston on presidents and foreign policy crises. The speech was part of the library's "Responding to Terrorism" series. We excerpted the speech on "Special Coverage;" Below is the speech in its entirety.