Daniel Ellsberg, famous for leaking the Pentagon Papers and his activism against nuclear weapons, announced recently that he has been diagnosed with terminal cancer.

Mr. Ellsberg, now 91, copied the military’s secret 7,000-page history of the Vietnam War and gave it to The New York Times and The Washington Post in 1971. The government sued to stop publication, but the Supreme Court defended the First Amendment right of a free press against prior restraint.