1971: the Pentagon Papers: when The Times published a secret study of the war in Vietnam, it touched off a constitutional battle with the government. How far does freedom of the press go?

• Author: Liptak, Adam

The front-page article that most interested President Richard M. Nixon when he picked up the Sunday New York Times on June 13,1971, concerned his daughter Tricia, who had been married the day before at the White House.

Nixon paid less attention to two other articles on that day's front page, both concerning the Pentagon Papers, a secret study of the Vietnam War by the Defense Department that covered the years 1945 to 1968. Inside the newspaper, there were three pages of excerpts from the study, along with coverage of the war itself, which would not end until 1975.

Those articles and Nixon's later efforts to stop The Times from publishing more about the Pentagon Papers would lead to one of the most important First Amendment cases in American history, one that played a huge role in defining just how free the press should be to report on the workings of government.

Neil Sheehan, a Times reporter, had obtained the study that March from Daniel Ellsberg, a former Pentagon and State Department official who had secretly copied the 7,000-page report in the hope of making it public. For three months, Sheehan, along with other Times reporters and editors, pored over the documents, eventually moving the project to the Hilton Hotel in New York to maintain security.

IT DOESN'T HURT US'

The study showed, among many other things, that over the years the federal government had misled the public about the reasons behind the war and the scope and effectiveness of the war effort.

Executives and lawyers at The Times argued among themselves about whether publishing government secrets during wartime was lawful, patriotic, or proper. (In the end, The Times's regular law firm refused to represent the paper in the case.)

Though The Times announced that the Sunday articles were only the start of a series that would describe and analyze the study, Nixon took no immediate action against the paper, reasoning that the disclosures would be more damaging to the reputations of his Democratic predecessors in the White House than to him.

The administration should "stay out of it," Nixon told an aide, because "it doesn't hurt us."

He changed his mind the next day, after intense lobbying from his national security adviser, Henry Kissinger, who said that allowing the publication of sensitive government secrets would hurt the nation's ability to conduct secret diplomacy around the world. "If other powers feel that we cannot control internal leaks," Kissinger said, "they will...