Although conviction of Ellsberg after publication remained a possibility, the government wanted more: to stop the damaging information from getting into the hands of the public. It wanted prior restraint on publication. Naturally, the U.S. government believed it was protecting national security from an outrageous theft. Despite a strong argument that national security would be compromised, the U.S. government did not achieve a permanent prior restraint. Two days after the Times began publishing Pentagon Papers documents, U.S. attorney general John Mitchell sent Justice Department lawyers to a federal district court to obtain a temporary injunction against the paper. Anticipating such a result, someone gave copies of the Pentagon Papers to several other U.S. papers. Then, when the Times was enjoined from publishing them, The Washington Post started publishing them. When the U.S. government enjoined the Post, the Boston Globe began publishing them, and so on. After legal maneuvering, the cases were consolidated and appealed swiftly to the U.S. Supreme Court.

The Supreme Court voted 6-3 against the Nixon Administration. Although all nine justices—writing separate opinions—upheld the concept of no prior restraint, they disagreed on whether such restraint could be justified by the extraordinary circumstances in this case. Justices Hugo L. Black, William O. Douglas, and—to a lesser degree— William J. Brennan, Jr., essentially maintained that the principle of no prior restraint was so strong that the government should never censor the press; Black and Douglas also argued against even the temporary injunctions, although such orders have historically been common in American law. Justices Thurgood Marshall, Potter Stewart, and Byron White (who voted with the first three justices to allow publication of the Pentagon Papers) held that the presumption against prior restraint was too strong in this case, but held open the option that someday there might be a national emergency in which prior restraint might be justified. They pointed out that the Nixon Administration’s case was further weakened because they had no law, duly passed by Congress, on which to rely, and that all the government could do was rely on a very weak legal argument that the president had a general power to protect the government from harm. Justices Warren Burger, Harry Blackmun, and John Harlan, voting against publication, maintained they were opposed to prior restraint but requested more time to look at the documents before making a final judgment whether a permanent restraining order should be issued.

By its 6-3 vote, the Court gave newspapers permission to publish the Pentagon Papers. However, because three “swing” justices expressed the view that there might be extreme circumstances in which prior restraint might be justified, there remained the possibility that a prior restraint might later be allowed. Nevertheless, publication of the documents was something that few, if any, other large countries would ever allow.

The original book form publication was edited by The New York Times staff under the title The Pentagon Papers (New York: Bantam Books, 1971). Documents on the U.S. negotiating procedure, a part of the original Defense Department study, were edited by George C. Herring, The Secret Diplomacy of the Vietnam War: The Negotiating Volumes of the Pentagon Papers (Austin: University of Texas, 1983). The best book covering the court case is Martin Shapiro’s edited volume, The Pentagon Papers and the Courts: A Study in Foreign Policy-Making and Freedom of the Press (San Francisco: Chandler, 1972). The case is given prominent consideration in Lucas A. Powe, Jr., The Fourth Estate and the Constitution: Freedom of the Press in America (Berkeley: University of California, 1991), and in Wallace Mendelson’s The American Constitution and Civil Liberties (Homewood, Ill.: Dorsey, 1981). A later study that incorporates considerable evidence not available earlier is David Rudenstine’s The Day the Press Stopped: A History of the Pentagon Papers Case (Berkeley: University of California Press, 1996).