In recent days, President Trump and his allies have amplified their calls for the whistleblower who sparked the impeachment inquiry to be identified, presenting the question of whether it would be a crime for the president to unmask the anonymous whistleblower.
According to four former top federal government officials who worked in intelligence and national security, the answer is no.
"If Trump thinks he knows the name, he can come out and say it, and he's probably as protected as anyone is," said Robert Litt, former general counsel for the Office of the Director of National Intelligence under President Barack Obama.
Litt and several other legal experts who talked to NPR said Trump uttering or tweeting the name could in theory trigger an article of impeachment for retaliating against a whistleblower, but it would not run afoul of any federal criminal statutes.
Similarly, if a news outlet, member of Congress or member of the public outed the whistleblower, legal experts said, no criminal law would be violated.
"There is no overarching protection for the identity of the whistleblower under federal law," said Dan Meyer, a lawyer and the former executive director of the intelligence community whistleblower program. "Congress has never provided that protection."
But that is not the same as saying there would be no repercussions for identifying the person whose complaint over Trump's dealings with Ukraine catalyzed the House impeachment investigation.
A member of Congress who reveals the whistleblower's identity could be removed from committees or face other legislative sanctions; a member of the public risks a civil lawsuit from the whistleblower's legal team, which has threatened to hold anyone who reveals the name personally liable if the disclosure results in harm to the whistleblower or the person's family.
Workplace retaliation against the whistleblower following disclosure would constitute a federal crime. But the act of unmasking itself is not unlawful, unless the person is a covert agent.
John McLaughlin, the former acting director of the CIA, said part of the reason why federal laws do not prohibit the president from outing a whistleblower is that the concept was never considered within the realm of possibility before Trump took office.
McLaughlin said there is a longstanding deference to the protection of whistleblowers who risk their jobs to expose corruption, waste and abuse that has largely prevented federal government officials from naming them.
"But as with so many of our supposed laws, compliance depends largely on a sense of integrity and voluntary compliance," McLaughlin said. "You just have to expect people to obey the law and the established practices, which of course in this administration has not always been the case."
Former Defense Secretary and CIA Director Leon Panetta said a presidential unmasking of the whistleblower would mark a historic event.
"The whole purpose of that law was to allow people to be able to speak to fraud or crimes they see within their jobs and without having to pay a price for vengeance and retribution," said Panetta, adding that having a president publicly reveal a whistleblower's name would be "unprecedented in history."
Whistleblower law "provides no protection"
There is a patchwork of whistleblower protections under federal law. The specific framework that applies to the whistleblower who filed a complaint against Trump is outlined in the Intelligence Community Whistleblower Protection Act of 1998.
The law bans retaliation against an employee for blowing the whistle on perceived wrongdoing. It requires the inspector general to keep the lid on the whistleblower's name, but it does not stop a member of Congress, a president or anyone else from identifying a whistleblower.
"[The Whistleblower Protection Act] provides no protection. It's the worst-named statute Congress has ever passed," Meyer said.
But, as Litt points out, if naming a whistleblower causes a chain reaction leading to a demotion or firing, or if the whistleblower is threatened with violence or is physically harmed, the legal situation could drastically change.
"Anybody who is thinking about outing the whistleblower has to take into account the possibility that if something happens to the whistleblower, there would be some civil liability for causing that to happen," Litt said. "And while disclosing the identity of the whistleblower isn't necessarily unlawful, creating a hostile work environment might be viewed as retaliation."
Trump naming the whistleblower seen as "an existential issue"
Some legal experts pushed back on the consensus view that identifying the whistleblower by itself is not a crime.
Stephen Kohn, a lawyer who has represented whistleblowers for more than 30 years and is the author of The New Whistleblower's Handbook, points to a 2014 law that spells out intelligence community whistleblower protections.
Under the statute, an agency cannot launch a reprisal against an intelligence community whistleblower. The prohibition is to be enforced by the president, Kohn says. And so, he argues, Trump revealing the whistleblower, or allowing the individual's name to come out, should be viewed as a type of reprisal.
"Disclosing the name of a whistleblower is perhaps one of the worst forms of retaliation," Kohn said. "Trump's obligations are not just to protect this whistleblower's identity. It only begins there. The law says he has to ensure that nobody in the executive branch leaks out his name."
Kohn said Trump could be subject to what's called a writ of mandamus, a court order to a government official to properly carry out his or her official duties. While no president in 215 years has been subject to a mandamus, Kohn says it should be on the table.
"These questions go to the heart of democracy and the rule of law," Kohn said. "This is an existential issue because you have the person with the legal responsibility to enforce and protect turning around and using that very authority to destroy."
Other legal experts say although whistleblower laws may not protect against outing a name, the behavior could be seen as criminal if viewed as an act of obstruction or witness retaliation in the congressional probe.
"The illegality is much broader than the whistleblower statute," said Tom Devine, the legal director for the Government Accountability Project. "It's illegal from a much broader context. It's about the free flow of information that's a prerequisite for law enforcement and for the Constitutional system of checks and balances."