Mr. Ellsberg and Mr. Kristol talked about the war with Iraq, protests against the war, the 1991 Gulf War, and related issues. They responded to audience telephone calls, faxes, and electronic mail. Mr. Ellsberg is the author of Secrets: A Memoir of Vietnam and the Pentagon Papers, published by Viking Press. Mr. Kristol is the co-author of The War over Iraq: Saddam's Tyranny and America's Mission, published by Encounter Books.