A temporary injunction was granted against The Progressive to prevent the publication of an article written by activist Howard Morland that purported to reveal the "secret" of the hydrogen bomb.

The defendants, Morland and the editors of The Progressive, would not accept security clearances, as they would have had to sign non-disclosure agreements that would have put restraints on their free speech (including, significantly, in written form), and so were not present at the in camera hearings.

[3] The military and scientific leaders of the Manhattan Project anticipated a need to release details of their wartime accomplishments, principally as a form of recognition for the participants who had labored in secrecy.

[6] In its October 8, 1945, issue, The New Republic took the position, emphasized with italics, that "there is no secret to be kept":[7] the knowledge of how to build an atomic bomb had been "the common property of scientists throughout the world for the last five years".

[7] President Harry S. Truman took a similar line in his first speech to Congress on nuclear matters that month, proclaiming that "the essential theoretical knowledge upon which the discovery is based is already widely known.

On September 1, 1945, Samuel K. Allison used the occasion of the announcement of the founding of the Institute for Nuclear Studies to call for freedom to research and develop atomic energy.

McMahon convened an executive session at which Federal Bureau of Investigation Director J. Edgar Hoover, Secretary of State James F. Byrnes and Groves were called to appear.

She dismissed objections that it would "give away the secret of the bomb",[17] asserting that America's advantage in nuclear weapons could only be temporary, whereas the bill could perpetuate the U.S. lead in scientific research.

[29] Scientists like Hans Bethe and George Gamow felt that Teller had committed the nation to an expensive crash program on the basis of a model that he knew was flawed.

"[35] In 1950, the Atomic Energy Commission asked Scientific American not to publish an article by Bethe that it claimed revealed classified information about the hydrogen bomb.

[36] The 1951 arrest of Klaus Fuchs, Harry Gold, David Greenglass, Morton Sobell and Julius and Ethel Rosenberg who, according to FBI Director J. Edgar Hoover, "stole the basic secrets of nuclear fission",[37] caused great concern.

On the contrary, in Near v. Minnesota 283 U.S. 697 (1931), Chief Justice Charles E. Hughes remarked that in wartime, "no one would question but that a government might prevent actual obstruction to its recruiting service or the publication of the sailing dates of transports or the number and location of troops.

The court subsequently upheld free speech exceptions such as restrictions on demonstrations in Cox v. New Hampshire, 312 U.S. 569 (1941), and censorship of motion pictures in Times Film Corp. v. City of Chicago, 365 U.S. 43 (1961).

In this case, the Supreme Court ruled 6–3 that the government had not reached the standard required by Near to justify prior restraint, but the concurring justices gave differing opinions about where the line should be drawn.

[45] In October 1978, Morland got Representative Ronald V. Dellums to submit a series of questions about plutonium production to the Department of Energy (DOE), the successor to the AEC.

[49][45] Morland claimed that "I am precisely the type of person the First Amendment was intended to protect: a political advocate whose ideas are unpopular with the general public and threatening to the government.

[50] His scientific background was minimal; he had taken five undergraduate courses in physics and chemistry as part of his Bachelor of Arts degree in economics at Emory University.

[50][51] "The notion that X-rays could move solid objects with the force of thousands of tons of dynamite," noted Morland, "was beyond the grasp of the science fiction writers of the time.

"[35] Day sent draft copies of Morland's article out to reviewers in late 1978 and early 1979, including Ron Siegel, a graduate student at Massachusetts Institute of Technology.

DOE officials, first in phone calls and then in person, attempted to dissuade The Progressive from publishing the article on the grounds that it contained "secret restricted data" as defined by the Atomic Energy Act.

They noted that prior restraint had been upheld by the courts before in matters of national security, and argued that the Pentagon Papers decision did not apply as the Atomic Energy Act specifically allowed for injunctive relief.

[63] In the Pentagon Papers case, Professor Alexander Bickel, an expert on the United States Constitution, when asked hypothetically if prior restraint could ever be justified, had told the court that he would draw the line at the hydrogen bomb.

[64] Because of the horrific nature of thermonuclear weapons, and the expectation that The Progressive would probably lose the case, mainstream media organizations feared that the result would be an erosion of freedom of the press.

The government affiants included classification officers, weapon lab scientists, the Secretaries of Energy, State, and Defense, and Nobel physics laureate Hans Bethe, whom Judge Warren cited as the star witness for the plaintiff.

Because of the importance of radiation implosion in civilian fusion research, Kidder had been quietly waging a campaign to declassify it for some years prior to the Progressive case.

The article was based upon information in the public domain, and was therefore neither a threat to national security nor covered by the Atomic Energy Act, which in any case did not authorize prior restraint, or was unconstitutional if it did.

In this, counsel relied on the United States v. Heine decision, in which Judge Learned Hand ruled that information in the public domain could not be covered by the Espionage Act of 1917.

[84] When The Daily Californian (the student-run college newspaper of the University of California at Berkeley), published excerpts from the Argonne letter on June 11, the DOE obtained a court order to prevent further publication.

In Morland's opinion, the article contributed to a wave of anti-nuclear activism in the late 1970s and early 1980s that resulted in, amongst other things, the closure of the Rocky Flats Plant near Denver.

[65] On September 30, 1980, the Justice Department issued a statement that it would not prosecute alleged violations of the Atomic Energy Act during the Daily Californian or The Progressive cases.