Attorney General Jeff Sessions announced that the Department of Justice is reviewing its policy on media subpoenas as part of an effort to combat leaks. (The Washington Post)

This post, originally published May 19, has been updated to address Friday's announcement by Attorney General Jeff Sessions that the Justice Department is taking additional steps to crack down on leaks.

Attorney General Jeff Sessions said Friday that the Justice Department “is reviewing policies affecting media subpoenas” as part of an effort to prevent government officials from leaking classified information to the media. The idea would be to compel journalists to reveal confidential sources and then prosecute those sources for illegal disclosures.

Following a familiar Washington script, Sessions sought to justify the threat of subpoenas as a lifesaving tactic.

“We respect the important role that the press plays and will give them respect, but it is not unlimited,” he said. “They cannot place lives at risk with impunity. We must balance the press's role with protecting our national security and the lives of those who serve in the intelligence community, the armed forces and all law-abiding Americans.”

This is a standard denunciation of leaks to the media. Republican and Democratic administrations alike often insist that disclosures of sensitive information to reporters put lives in danger. Is that true, or is the real threat to the image of the White House?

“There's plenty of huffing and puffing that goes on, plenty of attempts to hide embarrassments and incompetence,” said Jason Ross Arnold, a professor of political science at Virginia Commonwealth University and an expert on leaks. “Even in the national security realm, something comes out and maybe it's not that serious, but they make it seem like it is.”

Arnold, who recently completed a manuscript for his second book about leaks, said he is not familiar with a single case in which someone died as a direct result of a leak to the media.

In 2013, retired Brig. Gen. Robert Carr testified that an Afghan national was killed because Chelsea Manning provided battlefield reports containing roughly 900 names to WikiLeaks, which published the documents unredacted. Under cross examination, however, Carr acknowledged that the man who died was not among those identified in the war logs. The judge presiding over Manning's sentencing struck Carr's original assertion from the record.

An absence of direct casualties does not mean leaks are harmless, however.

“I think the strongest argument — and there are several — about negative consequences to security has more to do with indirect consequences,” Arnold said. “With the Manning leaks, she gave WikiLeaks these war logs with thousands upon thousands of detailed military operations. People who have access to big data techniques can find patterns and thus plan targets and develop strategies as a result.”

“We can't point to an individual who was killed,” Arnold added. “However, because of the new strategies and tactics adopted by terrorist groups — and because we've maybe been unable to follow them as well as we did before — disclosures have potentially, in some way, led to some of the attacks in Europe or even in the United States.”

It is important to note that major news outlets generally handle sensitive information more delicately than WikiLeaks does. For example, The Washington Post reported in May that Trump shared with Russian diplomats “details of an Islamic State terrorist threat related to the use of laptop computers on aircraft” and that he revealed the city in Islamic State territory where a U.S. intelligence partner detected the threat.

The article, by Greg Miller and Greg Jaffe, explained that “The Post is withholding most plot details, including the name of the city, at the urging of officials who warned that revealing them would jeopardize important intelligence capabilities.”

The Post's national editor, Scott Wilson, said in an interview that he and other editors take national security concerns into consideration when making publishing decisions.

“In national security stories such as this one, we are constantly trying to balance the public's right to know and the context the public needs to understand what we're reporting against information that could jeopardize, first and foremost, people and, second, ongoing U.S. or allied intelligence and military operations,” Wilson said.