Ellsberg’s talk, at 7:30 p.m. in the SSB Auditorium, is part of the University’s year-long Chautauqua series on “War and Peace.” The event is free and open to the public.

Ellsberg, 72, spent three years in the U.S. Marine Corps and later became a strategic analyst at the Rand Corporation and consultant to the Department of Defense and White House, specializing in problems related to the command and control of nuclear weapons, nuclear war plans and crisis decision-making.

He joined the Defense Department in 1964 as special assistant to Assistant Secretary of Defense John McNaughton, working on Vietnam. He transferred to the State Department in 1965 and served two years at the U.S. Embassy in Saigon.

On return to Rand in 1967, he worked on the top-secret McNamara study of U.S. decision-making in Vietnam, 1948-65, which later came to be known as the Pentagon Papers. In 1969, he photocopied the 7,000-page study and gave it to the Senate Foreign Relations Committee. In 1971, he gave it to 19 newspapers. His trial, on 12 felony counts under the Espionage Act posing a possible sentence of 115 years, was dismissed in 1973 on grounds of governmental misconduct due to illegal wiretapping and evidence tampering.

At one time, former Secretary of State Henry Kissinger called Ellsberg “the most dangerous man in America.”

Since the end of the Vietnam War, Ellsberg has lectured and written extensively on the dangers of the nuclear era and unlawful interventions.

His 2002 book, “Secrets: A Memoir of Vietnam and the Pentagon Papers,” has won numerous honors, including the American Book Award, and has prompted many to draw comparisons to the war in Iraq.

“There is an eerie timeliness about it,” the Los Angeles Times said of Ellsberg’s new book. “It underscores the need to understand history in areas of the world whose destines we presume to shape.”

The Economist said that the book “reminds us of the importance of dissent within democracies in time of war.”

Ellsberg’s “targets are just as often Democrats as Republicans,” the Seattle Times noted, “and one can easily accept his entire story as a tale of the mendacity of Big Government.”

The author rejects the patriot and traitor labels. Nor is Ellsberg a strict pacifist, although he opposes military aggression. “As a boy during World War II, I believed we were on the right side because we were fighting aggression,” he told the San Francisco Chronicle earlier this year, “and I felt the same way about Korea when I joined the Marines. But now I am in the horrifying position of seeing my country become the aggressor.”