Bremer was the chairman of the bipartisan National Commission on Terrorism. In June 2000, the commission published a report that predicted a terrorist attack on the United States on the scale of Pearl Harbor. Bremer previously served as ambassador-at-large for counterterrorism in the Reagan administration from 1986 to 1989 and U.S. ambassador to the Netherlands from 1983 to 1986. Bremer tells FRONTLINE that the "progressive degeneration" of American intelligence over the past 25 years is clear and has created a "risk-averse" culture at the CIA in terms of fighting terrorism.

Director of NSC Intelligence from 1984 to 1987, Cannistraro went on to serve as chief of operations for the CIA's Counterterrorism Center and to lead the CIA's investigation into the bombing of Pan Am 103. In this interview, he discusses the Reagan administration's response to terrorism in the 1980s and the factors that shaped its policy; the role of U.S. intelligence in combating terrorism, then and now; and what lessons have been learned, both by the U.S. and by terrorists who would target Americans.

Retired Marine Lt. Col. Bill Cowan, who served three tours of duty in Vietnam and was awarded the Silver Star for valor in combat, was sent to Beirut by the Pentagon in 1983. A military intelligence officer at the time, Cowan was charged with finding out who was responsible for bombing the U.S. Embassy in April of that year. Cowan says that when the U.S. military didn't respond to the many terrorist attacks against American targets during the 1980s, terrorists came to expect no retaliatory action from the U.S.

Hougan is a former Washington editor of Harper's Magazine and the author of two books about the intelligence community -- Spooks, about the use of intelligence agents in private industry, and Secret Agenda, his 1984 book about Watergate. Hougan, who says that the Israeli invasion of Lebanon had disastrous effects on the U.S. and its military policies, says the U.S. military should deal with Osama bin Laden with "knives and spies, not with lawyers."

Robert C. "Bud" McFarlane served as national security adviser to President Ronald Reagan from 1983 to 1985. During that time, the administration faced the deadly attack on the U.S. Marine barracks in Beirut; the abduction of the CIA's Beirut station chief, William Buckley; the bombing of the U.S. Embassy annex northeast of Beirut; the hijacking of TWA 847; and the commandeering of the Achille Lauro in the Mediterranean Sea. Here, McFarlane offers his personal perspective on how the debates within the Reagan administration shaped the U.S. response to these events and others, and led to the U.S. policy of arms sales to Iran in exchange for hostages -- a policy McFarlane was largely responsible for carrying out.

Melhem is a Lebanese journalist who works as Washington bureau chief for the Lebanese daily newspaper As-Safir. He also reports for Al-Qabas, a newspaper based in Kuwait, and for Radio Montecarlo. In this interview, Melhem reviews the evolution of Arab and Muslim nations' perspective on U.S. policies and actions in the Middle East, especially during the U.S. intervention in Lebanon during the 1980s. He also explores how Osama bin Laden and his contemporaries differ from the militant Islamic movements such as the Lebanese Hezbollah, which confronted the Reagan administration.

A former U.S. State Department coordinator for counterterrorism during the 1980s, Oakley also has served as U.S. ambassador to Pakistan, Zaire and Somalia. The situation with the Taliban and Osama bin Laden in Afghanistan today, Oakley says, is similar in many ways to Beirut's landscape in the '80s.

Weinberger was secretary of defense in the Reagan administration from 1981 to 1987, during the U.S. military intervention in Beirut. He tells FRONTLINE that the lesson he took from the bombing of the Marine barracks was that the U.S. must only use combat forces in a clearly defined mission and only as a last resort. In a famous 1984 speech given to the National Press Club, Weinberger advocated restraint in what became known as the Weinberger Doctrine, which argued for limiting the use of combat forces to U.S. national interests. Much has been made over the years about the debate between Weinberger and Reagan's former Secretary of State George Shultz over the use of military force versus diplomacy when dealing with terrorism. In his interview, Weinberger calls the perceived conflict between himself and Shultz "largely mythological" and says he was arguing against the "blind use" of military force.

An assistant managing editor of investigative news for The Washington Post, Woodward is the author of several books on U.S. politics, leaders and government including, Veil: The Secret Wars of the CIA 1981-1987. Here, Woodward discusses the "one theme" that informed how the Reagan White House dealt with terrorism, the deep policy divisions within the administration, and its overall inconsistency and half-measures in pursuing a tough counterrorism policy.