What Is the Espionage Act and How Has It Been Used?

WASHINGTON — The Espionage Act, a World War I-era law once used to stamp out dissent, eventually became the government’s legal tool of choice against spies and unauthorized leakers. But now former President Donald J. Trump faces questions about whether he violated the act after the F.B.I. seized top secret documents that he had taken to his Mar-a-Lago residence in Florida.

In recent years, some on the left have criticized the law, saying it was used to prosecute people who leaked government secrets. Now Republicans are denouncing the act after the Justice Department referred to it in its search warrant to retrieve documents from Mr. Trump’s home in Palm Beach, Fla., including some that were marked classified.

What is the Espionage Act, and how was it first used?

Congress first passed the Espionage Act in 1917 at the urging of President Woodrow Wilson. In a bid to quell dissent against the United States’ support for World War I, the act prohibited obtaining or disclosing information related to national defense if it could be used at the expense of the United States or to the advantage of any foreign nation. In 1918, a set of amendments prohibited speech considered disloyal or abusive to the United States.

During the war, for example, the producer of a film, “The Spirit of ’76,” was prosecuted under the act and sentenced to prison in 1918 because the government believed the movie undermined the British, a World War I ally, and was therefore seditious, said Mark S. Zaid, a national security lawyer.

“There were rampant abuses,” Mr. Zaid said. “There were tons of First Amendment violations. It didn’t take them long to realize that was ridiculous and unacceptable.”

Those sedition amendments were repealed in 1921, and courts later invalidated convictions under those measures. Congress last modified the law in 1950, and since then, the act has not been significantly revised.

Does the act make it a crime to reveal classified information?

No. The law criminalizes the unauthorized retention or disclosure of information related to national defense that could harm the United States or aid its enemies. It was enacted decades before the executive branch established the current system of classifying national security secrets.

In normal circumstances, a document protected by the Espionage Act is almost certainly classified. But because the two protection systems, executive branch classification and the Espionage Act, work in parallel, a document does not need to be classified to be protected by the act.

Who has been prosecuted under the Espionage Act?

The law has been used to prosecute both spies and leakers. Those accused of spying under the act include Julius and Ethel Rosenberg in the 1950s for purportedly giving nuclear secrets to the Soviet Union; Aldrich Ames, a C.I.A. officer, who was charged for revealing the identities of American informants to the Soviet Union in 1994; and Robert Hanssen, an F.B.I. agent, who was sentenced to life in prison in 2002 after confessing to selling secrets to the Russians.

Prominent leak cases involving the act include that of Daniel Ellsberg, who leaked the Pentagon Papers by photocopying the secret history of the Vietnam War and giving it to The New York Times. He was initially charged with a felony under the Espionage Act, but the charges were later dismissed.

Reality Winner, a former military contractor, was not so lucky. In 2018, she was sentenced to five years in prison for leaking a classified intelligence report about Russian interference in the 2016 election to The Intercept.

How has the law been applied in recent years?

The highest-profile recent accusations of Espionage Act violations have involved leakers, not spies. It is not so much that the government is focusing more on leaks of classified information, rather that prosecutors have more tools at their disposal to make their case. With emails, text messages and other technology, the government can more easily trace a document and prove who leaked the information, Mr. Zaid said.

What does the act mean for Trump?

It is not clear why Mr. Trump had classified documents at Mar-a-Lago. There is no evidence yet that he was planning to release the material. Nevertheless, mishandling sensitive documents and removing them from a secure facility is still prohibited — and can put national secrets at risk.

It may be difficult to determine who precisely brought the secret documents to Mar-a-Lago, who decided to store them there and the extent of Mr. Trump’s direct involvement. It is also possible that if there were no unauthorized disclosure of the documents and prosecutors do not find any criminal intent, the Justice Department could decide not to prosecute. That could make an investigation into why the documents were taken to Mar-a-Lago particularly crucial.

One important caveat: The Espionage Act includes a gross negligence standard, meaning a prosecutor does not have to prove criminal intent. Still, legal experts say that for the government, the priority is likely retrieving classified and sensitive documents — and making sure they are properly stored rather than being in a box at Mar-a-Lago. If the government thinks it has reclaimed all of the secret documents, prosecutors could decide not to proceed further with a legal case. But how the investigation will unfold is unclear.

But what is clear, experts said, is that no matter Mr. Trump’s intent, the First Amendment is not at issue in this instance, unlike in leak cases.

“That is not a free-speech issue,” said Glenn Gerstell, the former general counsel for the National Security Agency. “There is no First Amendment right to take national defense information out of secure facilities and take it home.”

Has any president ever been charged with violating the act?

No. But in 1918, Eugene V. Debs, the socialist candidate for president, was sentenced to 10 years in prison for a speech criticizing the wartime draft. Still, three years later, Mr. Debs again ran for president, this time from prison.

Why are liberals and conservatives alike clamoring to revise the Espionage Act?

Senator Rand Paul, Republican of Kentucky, has cited the history of the Espionage Act to jail World War I dissenters in arguing for its repeal.

Alison Grinter Allen, the lawyer for Ms. Winner, also argues the law should be revised. She notes her client was not able to present evidence to a jury about the content of the classified information she leaked or make an argument about why the public had a right to know what she had disclosed.

“The main problem with the Espionage Act is that you are not really allowed to make an appeal to fairness or the public interest,” she said. “That makes it really hard to defend against.”

But defenders of the law said such a change would undermine national security. The director of national intelligence has begun to examine whether too much material is unnecessarily deemed highly classified. Mr. Gerstell, formerly of the National Security Agency, welcomed that effort, but said changing the law to allow people to argue they can release information because they believe it is in the public interest goes too far.

“If someone makes the wrong decision, the wrong call, they’re too aggressive, our nation suffers as a whole,” he said. “That’s not going to be a good outcome for us. And that’s not the proper balance.”