WASHINGTON (NYTIMES) - Julian Assange's indictment on 17 counts of violating the Espionage Act for his role in obtaining and publishing secret military and diplomatic documents in 2010 raises profound First Amendment issues.

The new charges were part of an expanded indictment obtained by the Trump administration that significantly raised the stakes of the legal case against Assange, who is already fighting extradition proceedings in London based on an earlier hacking-related count brought by federal prosecutors in Northern Virginia.

The charges are the latest twist in a career in which Assange has morphed from a crusader for radical transparency to fugitive from a Swedish sexual assault investigation, to tool of Russia's election interference, to criminal defendant in the United States.

Assange vaulted to global fame nearly a decade ago as a champion of openness about what government secrets do. But with this indictment, he has become the target for a case that could open the door to criminalising activities that are crucial to American investigative journalists who write about national security matters.

The case has nothing to do with Russia's election interference in 2016, when Assange's organisation published Democratic e-mails stolen by Russia as part of its covert efforts to help elect President Donald Trump. Instead, it focuses on Assange's role in the leak of hundreds of thousands of State Department cables and military files by former Army intelligence analyst Chelsea Manning.

Justice Department officials did not explain why they decided to charge Assange under the Espionage Act - a step also debated within the Obama administration but ultimately not taken. Although the indictment could establish a precedent that deems actions related to obtaining, and in some cases publishing, state secrets to be criminal, the officials sought to minimise the implications for press freedoms.

They noted that most of the new charges were related to obtaining the secret document archives, as opposed to publishing them. In the counts that deemed the publication of the files a crime, prosecutors focused on a handful of documents revealing the names of people who provided information to the US in dangerous places like war zones.

"Some say that Assange is a journalist and that he should be immune from prosecution for these actions," Mr John Demers, the head of the Justice Department's National Security Division, said at a briefing with reporters. "The department takes seriously the role of journalists in our democracy and we thank you for it. It is not and has never been the department's policy to target them for reporting."

But Assange, he said, was "no journalist". Mr Demers accused him of conspiring with Manning to obtain classified information. "No responsible actor, journalist or otherwise, would purposefully publish the names of individuals he or she knew to be confidential human sources in a war zone, exposing them to the gravest of dangers," he said.

For the purposes of press freedoms, what matters is not who counts as a journalist, but whether journalistic activities - whether performed by a "journalist" or anyone else - can be crimes in America. The Trump administration's move could establish a precedent used to criminalise future acts of national-security journalism, said Mr Jameel Jaffer of the Knight First Amendment Institute at Columbia University.

"The charges rely almost entirely on conduct that investigative journalists engage in every day," he said. "The indictment should be understood as a frontal attack on press freedom."

Mr Demers left the press briefing without taking questions, and a Justice Department official who stayed behind to answer questions on the condition that he would not be named would not address any about how most of the basic actions the indictment deemed felonies by Assange differed in a legally meaningful way from ordinary national-security investigative journalism - encouraging sources to provide secret information of news value and, obtaining it without the government's permission and then publishing portions of it.

Notably, The New York Times, among many other news organisations, obtained precisely the same archives of documents from WikiLeaks, without authorisation from the government - the act that most of the charges addressed. While The Times did take steps to withhold the names of informants in the subset of the files it published, it is not clear how that is legally different from publishing other classified information.

Mr Barry J. Pollack, a lawyer for Assange, said his client was being charged with a crime "for encouraging sources to provide him truthful information and for publishing that information". That dramatic step, he said, removed the "fig leaf" that the case about his client was only about hacking.

"These unprecedented charges demonstrate the gravity of the threat the criminal prosecution of Julian Assange poses to all journalists in their endeavour to inform the public about actions that have been taken by the US government," he said.

For most of American history, it was rare for the government to treat the leaking of its secrets to the news media as a crime. But starting in the second half of the George W. Bush administration and accelerating during the Obama administration, the Justice Department began making much more routine use of the Espionage Act to go after officials who provided information to the public through reporters, as opposed to actual spies. The World War I-era law criminalises the disclosure of potentially damaging national security secrets to someone not authorised to receive them.

On its face, the Espionage Act could also be used to prosecute reporters who publish government secrets. But many legal scholars believe that prosecuting people for acts related to receiving and publishing information would violate the First Amendment.

That notion has never been tested in court, however, because until now the government has never brought such charges. The closest it came was indicting two lobbyists for a pro-Israel group in 2005 who received classified information about American policy towards Iran and passed it on, but that case fell apart after several sceptical pre-trial rulings by a judge and the charges were dropped.

Though he is not a conventional journalist, much of what Assange does at WikiLeaks is difficult to distinguish in a legally meaningful way from what traditional news organisations like The Times do: seek and publish information that officials want to be secret, including classified national security matters, and take steps to protect the confidentiality of sources.

The Obama administration had also weighed charging Assange, but rejected that step out of fears that it would chill investigative journalism and could be struck down as unconstitutional. A Justice Department official declined to address whether there was any new evidence that had come to light recently or whether the Trump administration had simply decided to take a step the Obama administration had shied away from.

The three charges that squarely addressed Assange's publication of government secrets were focused on a handful of files that contained the names of people who had provided information to the US in dangerous places like the Afghanistan and Iraq war zones, and authoritarian states like China, Iran and Syria.

The evidence laid out in the indictment against Assange mapped onto information presented by military prosecutors in the 2013 court-martial of Manning. Prosecutors in her case also alleged that her actions endangered the people whose names were revealed in the documents when Assange published them, though they presented no evidence that anyone was killed as a result.

A Justice Department official declined to say whether any such evidence now exists, but stressed that prosecutors would need to prove in court only what they say in the indictment: that publication put people in danger.

Manning was sentenced to 35 years in prison - by far the longest punishment for a leak case in American history. But in one of his last acts in office, president Barack Obama commuted most of the remainder of her sentence in January 2017.

She is now back in jail again, after a judge held her in contempt for refusing to testify about her interactions with Assange before the grand jury in the Eastern District of Virginia that indicted him.