Because of governmental misconduct and illegal evidence-gathering (committed by the same people who would later be involved in the Watergate scandal), and his defense by Leonard Boudin and Harvard Law School professor Charles Nesson, Judge William Matthew Byrne Jr. dismissed all charges against Ellsberg in May 1973.

He studied at King's College, Cambridge, for a year through funding from the Woodrow Wilson National Fellowship Foundation, initially for a diploma in economics and then changed his credits toward a PhD in the subject, before returning to Harvard.

[6] He concentrated on nuclear strategy, working with leading strategists such as Herman Kahn and challenging the existing plans of the United States National Security Council and Strategic Air Command.

Now known as the Ellsberg paradox,[8] it formed the basis of a large literature that has developed since the 1980s, including approaches such as Choquet expected utility and info-gap decision theory.

In 1967, he contributed with 33 other analysts to a top-secret 47-volume study of classified documents on the conduct of the Vietnam War, commissioned by Defense Secretary McNamara and supervised by Leslie H. Gelb and Morton Halperin.

In April 1968, Ellsberg attended a Princeton University conference on "Revolution in a Changing World", where he met Gandhian peace activist Janaki Natarajan Tschannerl from India, who had a profound influence on him, and Eqbal Ahmed, a Pakistani fellow at the Adlai Stevenson Institute later to be indicted with Rev.

In late 1969, with the assistance of his former RAND Corporation colleague Anthony Russo, Ellsberg secretly made several sets of photocopies of the classified documents to which he had access; these later became known as the Pentagon Papers.

Further, as an editor of The New York Times was to write much later, these documents "demonstrated, among other things, that the Johnson Administration had systematically lied, not only to the public but also to Congress, about a subject of transcendent national interest and significance".

[25] Ellsberg allowed some copies of the documents to circulate privately, including among scholars at the Institute for Policy Studies (IPS), Marcus Raskin and Ralph Stavins.

Meanwhile, while eluding an FBI manhunt for thirteen days, Ellsberg gave the documents to Ben Bagdikian, then-national editor of The Washington Post and former RAND Corporation colleague, in a Boston-area motel.

Two days prior to the Supreme Court's decision, Ellsberg publicly admitted his role in releasing the Pentagon Papers to the press, and surrendered to federal authorities at the U.S. Attorney's office in Boston.

[38] Aides Egil Krogh and David Young, under the supervision of John Ehrlichman, created the "White House Plumbers", which would later lead to the Watergate burglaries.

Richard Holbrooke, a friend of Ellsberg, came to see him as "one of those accidental characters of history who show the pattern of a whole era" and thought that he was the "triggering mechanism for events which would link Vietnam and Watergate in one continuous 1961-to-1975 story.

Krogh and Young sent a memo to Ehrlichman seeking his approval for a "covert operation [to] be undertaken to examine all of the medical files still held by Ellsberg's psychiatrist", Lewis Fielding.

1" in Ehrlichman's notes – was carried out by White House Plumbers Hunt, Liddy, Eugenio Martínez, Felipe de Diego, and Bernard Barker (the latter three were, or had been, recruited CIA agents).

Their trial commenced in Los Angeles on January 3, 1973, presided over by U.S. District Judge William Matthew Byrne Jr. Ellsberg tried to claim that the documents were "illegally" classified to keep them not from an enemy, but from the American public.

[48] It was also revealed in 1973, during Ellsberg's trial, that the telephone calls of Morton Halperin, a member of the U.S. National Security Council staff suspected of leaking information about the secret U.S. bombing of Cambodia to The New York Times, were being recorded by the FBI at the request of Henry Kissinger to J. Edgar Hoover.

[49] Halperin and his family sued several federal officials, claiming the wiretap violated their Fourth Amendment rights and Title III of the Omnibus Crime Control and Safe Streets Act of 1968.

The book included a revised version of Ellsberg's earlier award-winning "The Quagmire Myth and the Stalemate Machine", originally published in Public Policy, and ends with "The Responsibility of Officials in a Criminal War".

Reflecting on his time in government, Ellsberg said the following, based on his extensive access to classified material:[56] The public is lied to every day by the President, by his spokespeople, by his officers.

According to the documents, US military leaders supported a first-use nuclear strike even though they believed China's ally, the Soviet Union, would retaliate and millions of people would perish.

He assumed the Pentagon was involved again in contingency planning for a nuclear strike on China should a military conflict with conventional weapons fail to deliver a decisive victory.

[57] In releasing the classified documents, Ellsberg offered himself as a defendant in a test case challenging the U.S. Justice Department's use of the Espionage Act of 1917 to punish whistleblowers.

"[58] During the runup to the 2003 invasion of Iraq he warned of a possible "Tonkin Gulf scenario" that could be used to justify going to war, and called on government "insiders" to go public with information to counter the Bush administration's pro-war propaganda campaign, praising Scott Ritter for his efforts in that regard.

[64] In a speech on March 30, 2008, in San Francisco's Unitarian Universalist church, Ellsberg observed that House Speaker Nancy Pelosi does not have the authority to declare impeachment "off the table", as she had done with respect to George W. Bush.

[74] On June 10, 2013, Ellsberg published an editorial in The Guardian newspaper praising the actions of former Booz Allen worker Edward Snowden in revealing top-secret surveillance programs of the NSA.

He said that his primary job from 1958 until releasing the Pentagon Papers in 1971 was as a nuclear war planner for United States presidents Eisenhower, Kennedy, Johnson, and Nixon.

He concluded that United States nuclear war policy was completely crazy and he could no longer live with himself without doing what he could to expose it, even if it meant he would spend the rest of his life in prison.

His aircraft were equipped with Mark 28 thermonuclear weapons with a yield of 1.1 megatons each, roughly half the explosive power of all the bombs dropped by the U.S. in World War II both in Europe and the Pacific.

[93] In Russia, this included a semi-automatic "Dead Hand" system, whereby a nuclear explosion in Moscow, whether accidental or by a foreign state or terrorists, would induce low-level officers to launch ICBMs toward targets in the U.S., presumed to be the origin of such attacks.