Our mission at The New York Times is to seek the truth and help people understand the world. That takes many forms, from investigations on sexual abuse that helped spark the global #MeToo movement; to expert reporting that reveals how technology is reshaping every facet of modern life; to important and hard-hitting cultural commentary, like when we proclaimed “the Aperol spritz is not a good drink.”

But at a moment when surging nationalism is leading people to retreat inward, one of the most important jobs of The Times is to shine a light outward.

The Times is privileged to be one of the few news organizations with the resources to cover the world in all its complexity. And with that comes a responsibility to go where the story is, no matter the danger or hardship.

Every year, we put reporters on the ground in more than 160 countries. We’re in Iraq and Afghanistan, covering the violence and instability wrought by decades of war. We’re in Venezuela and Yemen, reporting on how corruption and conflict have led to mass starvation. We’re in Myanmar and China, eluding government monitors to investigate the systematic persecution of the Rohingya and Uighurs.

These assignments carry considerable risks. In recent years, my colleagues have suffered injuries from land mines, car bombs and helicopter crashes. They’ve been beaten by gangs, kidnapped by terrorists and jailed by repressive governments. When militants attacked a Nairobi mall, you could spot our journalist in the crowd because he was the only one running toward the gunfire.

Having covered conflicts since the American Civil War, we’ve learned from experience how to support and protect our journalists in the field. In any given year, our newsroom budget includes funding for bulletproof vests, hazmat suits and armored cars. We develop detailed security plans for high-risk assignments, and our journalists themselves prepare obsessively. C.J. Chivers, a former Marine who spent years reporting on war for The Times, trained himself to lift the weight of his photographer, so he could carry that person to safety if that person were shot or struck by shrapnel.

Those of us leading The Times find it hard not to worry, knowing we have colleagues on the ground where war is raging, disease is spreading and conditions deteriorating. But we’ve long taken comfort in knowing that in addition to all our own preparations and all our own safeguards, there has always been another, critical safety net: the United States government, the world’s greatest champion of the free press.

Over the last few years, however, something has dramatically changed. Around the globe, a relentless campaign is targeting journalists because of the fundamental role they play in ensuring a free and informed society. To stop journalists from exposing uncomfortable truths and holding power to account, a growing number of governments have engaged in overt, sometimes violent, efforts to discredit their work and intimidate them into silence.

This is a worldwide assault on journalists and journalism. But even more important, it’s an assault on the public’s right to know, on core democratic values, on the concept of truth itself. And perhaps most troubling, the seeds of this campaign were planted right here, in a country that has long prided itself on being the fiercest defender of free expression and a free press.

Let me start by stating the obvious: The media aren’t perfect. We make mistakes. We have blind spots. We sometimes drive people crazy.

But the free press is foundational to a healthy democracy and arguably the most important tool we have as citizens. It empowers the public by providing the information we need to elect leaders and the continuing oversight to keep them honest. It bears witness to our moments of tragedy and triumph and provides the shared baseline of common facts and information that bind communities together. It gives voice to the disadvantaged and doggedly pursues the truth to expose wrongdoing and drive change.

It is also under great and growing pressure. In the two decades since I began working at The Providence Journal, writing about daily life in the small town of Narragansett, the press has faced a cascading series of existential challenges.

The advertising-based business model that supported journalism collapsed, causing the loss of more than half of the country’s journalism jobs. Google and Facebook became the most powerful distributors of news and information in human history, accidentally unleashing a historic flood of misinformation in the process. And a rising drumbeat of legal efforts — from whistleblower prosecutions to libel suits — aims to weaken long-standing safeguards for journalists and their sources.

Around the world, the threat journalists face is far more visceral. Last year was the most dangerous year on record to be a journalist, with dozens killed, hundreds imprisoned and untold thousands harassed and threatened. Those include Jamal Khashoggi, who was murdered and dismembered by Saudi assassins, and Maksim Borodin, a Russian journalist who fell to his death from the balcony of his apartment after revealing the Kremlin’s covert operations in Syria.

The hard work of journalism has long carried risks, especially in countries without democratic safeguards. But what’s different today is that these brutal crackdowns are being passively accepted and perhaps even tacitly encouraged by the president of the United States.

This country’s leaders have long understood that the free press is one of America’s greatest exports. Sure, they’d complain about our coverage and bristle at the secrets we brought to light. But even as domestic politics and foreign policy would change, a baseline commitment to protecting journalists and their rights would remain.

When four of our journalists were beaten and held hostage by the Libyan military, the State Department played a critical role in securing their release. Interventions like this were often accompanied by a stern reminder to the offending government that the United States defends its journalists.

The current administration, however, has retreated from our country’s historical role as a defender of the free press. Seeing that, other countries are targeting journalists with a growing sense of impunity.

This isn’t just a problem for reporters; it’s a problem for everyone, because this is how authoritarian leaders bury critical information, hide corruption, even justify genocide. As Sen. John McCain once warned, “When you look at history, the first thing that dictators do is shut down the press.”

To give you a sense of what this retreat looks like on the ground, let me tell you a story I’ve never shared publicly before. Two years ago, we got a call from a United States government official warning us of the imminent arrest of a New York Times reporter based in Egypt named Declan Walsh. Though the news was alarming, the call was actually fairly standard. Over the years, we’ve received countless such warnings from American diplomats, military leaders and national security officials.

But this particular call took a surprising and distressing turn. We learned the official was passing along this warning without the knowledge or permission of the Trump administration. Rather than trying to stop the Egyptian government or assist the reporter, the official believed, the Trump administration intended to sit on the information and let the arrest be carried out. The official feared being punished for even alerting us to the danger.

Unable to count on our own government to prevent the arrest or help free Declan if he were imprisoned, we turned to his native country, Ireland, for help. Within an hour, Irish diplomats traveled to his house and safely escorted him to the airport before Egyptian forces could detain him.

We hate to imagine what would have happened had that brave official not risked their career to alert us to the threat.

Eighteen months later, another of our reporters, David Kirkpatrick, arrived in Egypt and was detained and deported in apparent retaliation for exposing information that was embarrassing to the Egyptian government. When we protested the move, a senior official at the United States Embassy in Cairo openly voiced the cynical worldview behind the Trump administration’s tolerance for such crackdowns. “What did you expect would happen to him?” he said. “His reporting made the government look bad.”

Since assuming office, President Trump has tweeted about “fake news” nearly 600 times. His most frequent targets are independent news organizations with a deep commitment to reporting fairly and accurately. To be absolutely clear, The Times and other news organizations are fair game for criticism. Journalism is a human enterprise, and we sometimes make mistakes. But we also try to own our mistakes, to correct them and to rededicate ourselves every day to the highest standards of journalism.

But when the president decries “fake news,” he’s not interested in actual mistakes. He’s trying to delegitimize real news, dismissing factual and fair reporting as politically motivated fabrications.

So when The Times reveals his family’s fraudulent financial practices, when The Wall Street Journal reveals hush money paid to a porn star, when The Washington Post reveals his personal foundation’s self-dealing, he can sidestep accountability by simply dismissing the reports as “fake news.”

Even though all those stories — and countless more that he’s labeled fake — have been confirmed as accurate, there is evidence that his attacks are achieving their intended effect: One recent poll found that 82% of Republicans now trust President Trump more than they trust the media. One of the president’s supporters was recently convicted of sending explosives to CNN, one of the most frequent targets of the “fake news” charge.

But in attacking American media, President Trump has done more than undermine his own citizens’ faith in the news organizations attempting to hold him accountable. He has effectively given foreign leaders permission to do the same with their countries’ journalists and even given them the vocabulary with which to do it.

They’ve eagerly embraced the approach. My colleagues and I recently researched the spread of the phrase “fake news,” and what we found is deeply alarming: In the past few years, more than 50 prime ministers, presidents and other government leaders across five continents have used the term “fake news” to justify varying levels of anti-press activity.

The phrase has been used by Prime Minister Viktor Orban in Hungary and President Recep Tayyip Erdogan in Turkey, who have levied massive fines to force independent news organizations to sell to government loyalists. It’s been used by President Nicolás Maduro in Venezuela and President Rodrigo Duterte in the Philippines, who have attacked the press as they’ve led bloody crackdowns.

In Myanmar, the phrase is used to deny the existence of an entire people who are systematically targeted with violence to force them out of their country. “There is no such thing as Rohingya,” a leader in Myanmar told The Times. “It is fake news.”

The phrase has been used to jail journalists in Cameroon, to suppress stories about corruption in Malawi, to justify a social media blackout in Chad, to prevent overseas news organizations from operating in Burundi. It has been used by the leaders of our longtime allies, like Mexico and Israel. It has been used by longtime rivals, like Iran, Russia and China.

It has been used by liberal leaders, like Ireland’s prime minister, Leo Varadkar. It’s been used by right-wing leaders, like Brazil’s president, Jair Bolsonaro. Standing next to President Bolsanaro in the Rose Garden, President Trump said, “I’m very proud to hear the president use the term ‘fake news.’”

Our foreign correspondents have experienced the weaponization of the “fake news” charge firsthand. Last year, Hannah Beech, who covers Southeast Asia, was at a speech by Prime Minister Hun Sen of Cambodia. In the middle of his remarks, Mr. Hun Sen uttered a single phrase in English: “The New York Times.” He said that The Times was so biased that it had been given a ‘fake news’ award by President Trump, and he threatened that if our story didn’t support his version of the truth, there would be consequences.

Hannah felt a growing hostility in the crowd of thousands as the prime minister searched her out and warned, “The Cambodian people will remember your faces.”

I have raised these concerns with President Trump. I’ve told him that these efforts to attack and suppress independent journalism is what the United States is now inspiring abroad. Though he listened politely and expressed concern, he has continued to escalate his anti-press rhetoric, which has reached new heights as he campaigns for reelection.

President Trump is no longer content to delegitimize accurate reporting as “fake news.” Now, he has taken to demonizing reporters themselves, calling them “the true enemy of the people” and even accusing them of treason. With these phrases, he has not just inspired autocratic rulers around the world, he has also borrowed from them.

The phrase “enemy of the people” has a particularly brutal history. It was used to justify mass executions during the French Revolution and the Third Reich. And it was used by Lenin and Stalin to justify the systematic murder of Soviet dissidents.

The treason charge is perhaps the most serious a commander in chief can make. By threatening to prosecute journalists for invented crimes against their country, President Trump gives repressive leaders implicit license to do the same.

In the United States, the Constitution, the rule of law and a still-robust news media act as a constraint. But abroad, foreign leaders can silence journalists with alarming effectiveness.

Nick Casey, a Times reporter who was repeatedly threatened and ultimately barred from Venezuela for aggressive reporting on the brutal Maduro regime, stressed how much more serious consequences can be for local journalists. “If this is what countries are capable of doing to me, as a Times reporter, what are they capable of doing to their own citizens?” he asked. “Far worse. And I’ve seen it.”

Even as we worry about the dangers our own reporters face, those dangers usually pale in comparison to what courageous local journalists confront around the world. They search for truth and report what they find, knowing that they and their loved ones are vulnerable to fines, arrests, beatings, torture, rape and murder. These reporters are the front-line soldiers in the battle for press freedom, and they’re the ones who pay the greatest price for President Trump’s anti-press rhetoric.

The cases of intimidation and violence I’ve discussed today are just a few of the ones we know about. On any given day, similar stories are unfolding around the world, many of which will never surface or be recorded. In many places, fear of reprisal is great enough that it has a chilling effect — stories go unpublished; secrets remain buried; wrongdoing remains covered up.

This is a perilous moment for journalism, for free expression and for an informed public. But the moments and places where it is most difficult and dangerous to be a journalist are the moments and places where journalism is needed most.

A tour of our nation’s history reminds that the role of the free press has been one of the few areas of enduring consensus, transcending party and ideology for generations. Thomas Jefferson wrote that “the only security of all is in a free press.” John F. Kennedy called the free press “invaluable” because “without debate, without criticism, no administration and no country can succeed — and no republic can survive.” Ronald Reagan went even further, saying, “There is no more essential ingredient than a free, strong and independent press to our continued success in what the Founding Fathers called our ‘noble experiment’ in self-government.”

Despite this tradition of American presidents defending the free press, I do not believe President Trump has any intention of changing course or muting his attacks on journalists. If recent history is any guide, he may point to my comments today and claim that The Times has a political vendetta against him. To be clear, I’m not challenging the president’s recklessness because of his party, his ideology or his criticism of The Times.

I’m sounding the alarm because his words are dangerous and having real-world consequences around the globe. But even if the president ignores this alarm and continues on this path, there are important steps the rest of us can take to protect the free press and support those who dedicate their lives to seeking truth around the world.

It starts with understanding the stakes. The First Amendment has served as the world’s gold standard for free speech and the free press for two centuries. It has been one of the keys to an unprecedented flourishing of freedom and prosperity in this country and, through its example, around the world. We cannot allow a new global framework, like the repressive model embraced by China, Russia and others, to take hold.

This means, in the face of mounting pressure, news organizations must hold fast to the values of great journalism — fairness, accuracy, independence — while opening ourselves so the public can better understand our work and its role in society. We need to keep chasing the stories that matter, regardless of whether they’re trending on Twitter. We cannot allow ourselves to be baited or applauded into becoming anyone’s opposition or cheerleader. Our loyalty must be to facts, not to any party or any leader, and we must continue to follow the truth wherever it leads, without fear or favor.

But the responsibility to stand up for the free press extends beyond news organizations. Business, nonprofit and academic communities, all of which rely on the free and reliable flow of news and information, have a responsibility to push back on this campaign, too. That is particularly true of tech giants like Facebook, Twitter, Google and Apple. Their track record of standing up to governments abroad is spotty at best; they’ve too often turned a blind eye to disinformation and, at times, permitted the suppression of real journalism.

But as they move even deeper into making, commissioning and distributing journalism, they also have a responsibility to start defending journalism.

Our political leaders need to step up, too. Those elected to uphold our Constitution betray its ideals when they undermine the free press for short-term political gain. Leaders from both parties should support independent journalism and fight anti-press efforts at home and abroad.

Here in the United States, that means rejecting efforts like frivolous lawsuits and investigations targeting government leaks that aim to chill aggressive reporting. And around the world, it means opposing the countless efforts underway to attack, intimidate and delegitimize journalists.

Finally, none of these efforts will make a difference unless you raise your voice. Care about where your news comes from and how it’s made. Find news organizations you trust and enable the expensive, arduous work of original reporting by buying a subscription. Support organizations like the Committee to Protect Journalists and Reporters Without Borders that defend journalists at risk around the world. Most of all, carve out a place for journalism in your everyday life and use what you learn to make a difference.

The true power of a free press is an informed, engaged citizenry. I believe in independent journalism and want it to thrive. I believe in this country and its values, and I want us to live up to them and offer them as a model for a freer and more just world.

The United States has done more than any other country to popularize the idea of free expression and to champion the rights of the free press. The time has come for us to fight for those ideals again.

In this Dec. 13, 2017, file photo, New York Times publisher A.G. Sulzberger poses for a photo on the 16th floor of the New York Times building in New York. (Damon Winter/The New York Times via AP, File)

A.G. Sulzberger is the publisher of The New York Times. This Op-Ed was originally delivered as a talk at Brown University on Monday.