You know something is amiss when a US-based foundation dedicated to monitoring and defending press freedom around the world feels compelled to set up a website to track it in the one place that has always held itself up as a beacon of free speech – the United States itself.

Earlier this year, the Freedom of the Press Foundation launched the US Press Freedom Tracker, along with 20 partners, including the Committee to Protect Journalists, Reporters Without Borders and the Knight First Amendment Institute at Columbia University. The site logs anything it regards as a threat to press freedom including arrests and assaults of journalists in the course of their jobs.

From 1 January 2017 until the beginning of December, the site listed 32 journalists arrested in the US; 24 incidents where journalists’ equipment was seized, stolen or damaged; 35 physical attacks on journalists, and five times when they were stopped at the border.

The site was set up after Donald Trump began making some of the most explicit attacks on the media in the history of the US presidency. That is hardly breaking news – anybody who has paid any attention to President Trump will know he routinely refers to the “failing” New York Times, and CNN as the “Clinton News Network”. He has described reporters in general as “scum” and “dishonest people”. As a candidate, he threatened to broaden libel laws to make it easier to sue journalists, and blacklisted both individual journalists and their news outlets from attending his campaign events. He has shut out those he doesn’t like from White House briefings, while his attorney general Jeff Sessions announced in August a new crackdown on leakers that includes a justice department review of the way it deals with media outlets publishing leaked information.

All this makes Steven Spielberg’s new movie, The Post, disturbingly relevant. The movie recalls the Nixon government’s attempt in 1971 to stop the Washington Post and the New York Times from publishing a secret report about the Vietnam war that became known as the Pentagon Papers.

It is a classic Hollywood rendering of the struggle between the government trying to cover up its lies to the American people and the newspapers’ determination to expose it. Most crucially, it reminds us of the essential role the media plays in a healthy functioning democracy.

“We have to be their check on power,” declares Post editor Ben Bradlee (Tom Hanks), as he argues the case for printing the story with publisher Katharine Graham (Meryl Streep) while she wrestles with the possibility of losing her business and winding up in prison in the process. “We have to hold them accountable. If we don’t, who will?”

Amid the persistent attacks on media credibility today, growing government intrusions on media freedom and the struggle for news organisations to survive in a digital world, it is easy to lose sight of that most fundamental principle.

I understand the pressure all too well. In December 2013, my two colleagues and I were arrested in Egypt on terrorism charges. In essence, we were accused of being propagandists for the Muslim Brotherhood, which at the time was the single most popular political force in the country.

We could have argued we were innocent victims caught up in a wider regional political struggle, and that we posed no threat to the government or the country. That would have been the easy course, but we understood it also would have been the wrong one.

Instead, we chose to call it out for what it was – part of an unprecedented crackdown on media freedom and the freedom of expression more broadly that has since seen some 60,000 people imprisoned on political charges and made Egypt the third-biggest jailer of journalists in the world. We were convicted and sentenced to seven years in prison, though under intense international pressure the authorities released us after more than 400 days behind bars.

In the end, despite demands from their investors to cave in and avoid a court battle, Bradlee and Graham decided to hold the line too. They went to the supreme court, along with the New York Times, to fight a government injunction, arguing that the public’s right to know is more important than the government’s right to censor information it claims could be damaging to national security.

The supreme court agreed. It voted 6-3 to back the papers – a decision that has become a key precedent in the struggle to protect media freedom in the US.

In a concurring opinion, Justice Potter Stewart explained why: “In the absence of the governmental checks and balances present in other areas of our national life, the only effective restraint upon executive policy and power in the areas of national defence and international affairs may lie in an enlightened citizenry – in an informed and critical public opinion which alone can here protect the values of democratic government,” he wrote. “For this reason, it is perhaps here that a press that is alert, aware, and free most vitally serves the basic purpose of the first amendment. For, without an informed and free press, there cannot be an enlightened people.”

Justice Stewart may have written that more than 45 years ago, but in the face of renewed pressure on journalists everywhere, it is just as pertinent now as it was then.

• The Post opens globally on 11 January