Daniel Ellsberg, an outspoken opponent of nuclear weapons known for exposing the government’s deception of the United States in the Vietnam War, has died of pancreatic cancer at the age of 92.
The Washington Post was first to report Ellsberg’s death on Friday, citing a statement from his family.
“My dear father, #DanielEllsberg, passed away this morning June 16 at 1:24am, four months after he was diagnosed with pancreatic cancer. His family surrounded him as he breathed his last. He died peacefully at home with no pain,” his son Robert said on Twitter on Friday.
While Ellsberg was known for his efforts to bring the trove of secret documents known as the “Pentagon Papers” to public attention, he remained active on many issues, such as the protection of whistleblowers and the danger of nuclear weapons, until the end of his life .
When the Pentagon Papers were leaked, Henry Kissinger, the mastermind behind America’s escalation of the Vietnam War and former President Richard Nixon’s national security adviser, called Ellsberg “the most dangerous man in America who must be stopped at all costs.”

Ellsberg, who worked as a military analyst on national security issues at the Pentagon and at the Rand Corporation, a prominent policy think tank, became dismayed by the U.S. war in Vietnam and leaked thousands of pages of documents detailing the administration’s lies about the war to the media 1971.
The incident sparked a landmark free speech battle that eventually reached the U.S. Supreme Court. Less than two weeks after the paper was published, the court ruled that the press had the right to publish Ellsberg’s leaked material, a key victory for efforts to expose government lies on issues such as national security.
In January 1973, the US government charged him with theft and conspiracy under the Espionage Act, which carries a maximum penalty of 115 years in prison. The charges were dismissed in May of that year, citing government misconduct and illegal evidence gathering.
Throughout his life, Ellsberg has opposed the use of the Espionage Act and has been a vocal advocate for the rights of whistleblowers such as Edward Snowden and Julian Assange, who both released classified documents to the public, Exposes government abuses such as illegal mass surveillance and the killing of civilians in U.S. wars overseas.
In a 2014 interview with Al Jazeera, Ellsberg spoke of the dangers of the broad classification of government documents and the “culture of secrecy” within the US national security agency.
“Challenging a culture of secrecy has become more difficult since 9/11. Just as it has become more difficult to challenge patently criminal, illegal, internationally prohibited practices — like torture,” he said.
Ellsberg was also a staunch opponent of nuclear weapons. His activism over the decades has resulted in dozens of arrests.

His 2017 book, “The Doomsday Machine: Confessions of a Nuclear War Planner,” details the dangers of nuclear weapons and their place in U.S. national security. This is based on his experience as a military analyst working on nuclear issues from 1958 to 1971.
In it, he describes a moment that marked a turning point in his life and worldview: Reading a government document estimating that some 600 million people would die in the first U.S. nuclear attack on the Soviet Union and its Warsaw Pact satellites, and China.
“I remember thinking the first time I held a piece of paper with a diagram on it. I thought, ‘This piece of paper shouldn’t exist. It shouldn’t exist. Not in America. Never anywhere.'”
He added, “From that day forward, I have had one of the most important goals of my life: to stop any such plan from being carried out.”
Ellsberg remained in touch with young people and activists until the end of his life, telling Al Jazeera in 2014 that he was “inspired” by his interactions with students on issues such as surveillance.
He dedicated The Doomsday Machine to “those who fight for the future of humanity”.