After US House of Representatives Democrats launched an impeachment inquiry last week, US President Donald Trump condemned the person responsible for the whistleblower complaint that set the wheels in motion, likening the whistleblower to “spies” who are guilty of “treason”.

It may be tempting to attribute this rhetoric to the President’s dictatorial streak, but the sentiment behind Trump’s words is all too familiar. Yes, many are portraying the anonymous intelligence official who blew the whistle on Trump as a hero, but all too often, Americans who reveal truths about government misdeeds are treated as traitors.

Take Edward Snowden. It has been six years since Snowden leaked a trove of secret documents that exposed the National Security Agency’s mass surveillance programme.

For this act of public service, Snowden was charged with violating the Espionage Act, forcing him to live in exile in Russia. Even as the latest whistleblower scandal was breaking, the Justice Department filed a lawsuit against Snowden over the release of his new memoir, Permanent Record, an absurd act of spite, considering that the book contains no details about surveillance that have not been previously reported.

“When the Government is embarrassed after being caught breaking the law, they say the people who revealed that lawbreaking have caused serious harm to national security,” Snowden explained in a recent interview on CBS. “This was the case of Daniel Ellsberg way back in the Vietnam War with the Pentagon Papers.”

Ellsberg, of course, is the godfather of modern whistleblowing. After his 1971 leak of the Pentagon Papers revealed that multiple US administrations had misled the public about their plans for war in Vietnam, Ellsberg faced charges under the Espionage Act.

Henry Kissinger famously labelled him “the most dangerous man in America who must be stopped at all costs”; but he was not stopped.

The charges against him were dropped after it was revealed that White House operatives had broken into his psychiatrist’s office in an attempt to discredit him, and he has gone on to a prolific career as a writer, lecturer and activist.

Now, his life’s work is being preserved and made available to the public. Last week, the University of Massachusetts at Amherst announced that it has acquired more than 500 boxes of Ellsberg’s papers, annotated books and photographs.

The massive collection includes analyses from his time at the Rand Corporation and the Defence Department, extensive notes from his criminal trial, and personal correspondence with the likes of Kissinger and Eugene McCarthy.

It also contains a wide range of materials from Ellsberg’s crucial work as an antiwar and antinuclear activist in the decades after his whistleblowing, work that informed his 2017 book, The Doomsday Machine: Confessions of a Nuclear War Planner.

Ellsberg’s papers will be housed in the archives of UMass’s W.E.B. Du Bois Library alongside the papers of the famed civil rights activist, another man so “dangerous” that the FBI had a 750-page file on him. They will give future scholars and activists valuable insight, not only into Ellsberg’s life, but also into key events in US history that are still relevant today.

In a phone interview, Ellsberg told me he is particularly excited that his archives will be digitised, a reflection of his commitment to the democratisation of information. He added that the public need to understand that we now face two “existential” crises as a result of the risks posed by nuclear war and catastrophic climate change. “Today, Greta Thunberg is the most dangerous person in the world,” he said, referring to the 16-year-old climate activist. “I am trying to channel her.”

As for the existing presidential scandal, Ellsberg sees clear historic parallels. “We’re back to Nixon and the redacted transcript.”

At the same time, Ellsberg said the complaint against Trump may be the start of a “new phase” in the long tradition of whistleblowing.

The American people should hope he is right. Telling the truth about the Government’s failings is not always popular, but it is among the highest forms of patriotism. Whistleblowers who put themselves at risk to inform the public deserve our gratitude, even when Trump is not the target of their revelations. As Ellsberg told The Boston Globe last week, “Officials in any country want to keep their secrets. What defines a democracy is that they don’t get to.”

• Katrina vanden Heuvel, editor and publisher of the Nation magazine, writes a weekly column for The Washington Post. She has also edited several books, including The Change I Believe In: Fighting for Progress in the Age of Obama (2011) and Meltdown: How Greed and Corruption Shattered Our Financial System and How We Can Recover (2009)