At the dawn of a turbulent era in American history, an inexperienced but media-savvy President, early in his first term, was obsessing about negative press.

John F. Kennedy, who had grown accustomed to compliant coverage, was running up against the limits of his power to control the public narrative when neither the world nor the press would read from his script. Halfway around the globe, a small band of foreign correspondents were undercutting the White House with stories that showed the United States becoming more deeply involved (and less successfully) than the government acknowledged in what would become the Vietnam War.

Relations between the Saigon press corps and the United States Embassy had deteriorated into "a mutual standoff of cold fury and hot shouts––Liar! Traitor! Scoundrel! Fool!––with an American foreign policy teetering precariously in the void between," wrote William Prochnau in Once Upon a Distant War, an under-appreciated account of fraught relations between the government and the press.

At his wit's end one day in 1962, Kennedy dialed up his long-time friend James Reston, the legendary columnist and New York Times Washington Bureau Chief with an urgent request, in the interest of national security: fire war reporter David Halberstam. Reston declined. Halberstam persevered, the war proving every bit the disaster he had foreseen. And even the President eventually lamented, upon reading the Times one morning, "why can I get this stuff from Halberstam when I can't get it from my own people?"

I read Prochnau on the advice of my editor at The Washington Post, just before I flew to Kuwait in early 2003, to cover the invasion of Iraq, embedded with a U.S. Marine infantry unit. I spent the better part of the succeeding three years living in, and writing about, Iraq, and clashing occasionally, though never spectacularly, with the U.S. Embassy there.

More recently, from 2009 to 2017, I was on the other side of those clashes, working on foreign policy in the Obama White House and State Department, dealing frequently with my former journalism colleagues along the way, who were covering our efforts.

I have thought a lot about both experiences since Donald Trump's Friday night tweet labeling the media "enemies of the American people," and about why his repeated assaults feel so different from those of his predecessors. The Founding Fathers set a course for such collisions by both recognizing the need for the government to keep secrets, and codifying the right of the press to ferret them out.

The relationship between the government and the press should be adversarial, as their missions are often at odds. As those seeking to downplay the current confrontation have rightly pointed out, this has resulted in a power struggle between that is as old as the Republic itself.

But Trump’s relationship with the media represents something new and potentially dangerous to both. He is the first President to publicly question the place of the media in American society itself. And his branding of the press as an "enemy" seems less an attempt to influence coverage than an invitation to repression and even violence.

The level of antipathy or collegiality between the government and the press has always moved in cycles of confrontation and detente.

Ironically, when I first left for Iraq 14 years ago, close watchers of media-government relations were most concerned by a burgeoning coziness epitomized by, for example, the star-studded White House Correspondents dinner, that resulted the appearance of journalists trading favorable coverage for access. (Defense Secretary James Mattis, who broke with the president in his characterization of the press as “the enemy,” was the commander of the division I embedded in).

Before the invasion of Iraq, when the Pentagon decided to let reporters "embed" themselves in military units for the first time since Vietnam, press critics warned that reporters would become cheerleaders for an event deserving serious scrutiny. After all, the theory went, it will be hard to remain objective when you ride, eat and sleep among people who are literally defending your life.

"They are not your friends," one of my editors told me, referring to the military, in our last meeting before my departure. "Basically everything they tell you will be a lie."

But while the press had failed to interrogate the Bush Administration's rationale for invading, almost as soon as the war began, reports describing what was happening on the ground differed sharply from the official line. If you believed the major newspapers and television networks, you knew the country was descending into insurgency and civil war. If you listened to the Green Zone press briefings, you may have thought Iraq, and indeed the entire Middle East, were on the cusp of a democratic flourishing.

That divide, which, like so many others, eventually resolved in favor of the press, as confirmed by a now infamous quote from Dan Senor, an American spokesman in Baghdad: "Off the record: Paris is burning. On the record: stability and security are returning to Iraq."

To its credit, the Bush Administration knew the Iraq reporters were not on the team, per se, but it did seek to use them for its own purposes. Access was extraordinary, and deliberately so. The theory, which proved correct, was that reporters were more likely to be impressed by grunts risking their lives for their country than by senior officers briefing on a base far from the front lines. In the end, the arrangement worked out well for both sides. Embedded coverage did tend to be more positive, but it also produced vivid and damning reports on things like American casualties and the killing of Iraqi civilians, that helped turn the public against the war.

While the Obama Administration largely avoided major breakdowns in relations with the press, we were far from immune from tensions. One of the few aspects of our tenure I am not proud of is that we oversaw more frequent use of law enforcement tools against journalists.

I joined the Administration determined to avoid having to spin my reporter friends and former colleagues, and initially steered clear of press-related government jobs. I came to appreciate the give-and-take with journalists who covered the State Department and deeply respected their mission. Still, I occasionally complained about stories, sometimes sharply. I once even decided to bar a newspaper reporter from flying to Europe on Secretary Kerry's plane because he had, in my view, inappropriately passed on information given to him off-the-record. He took a commercial flight, and we got on with our jobs.

It is clear, however, that the current standoff between Trump and the Washington press is a disturbing departure from these precedents.

First, as I have written previously, his assault on the press seems calculated not to influence coverage, but to destroy the credibility of the media so he can usurp the its traditional role as the arbiter of facts on which policy decisions are based. If the goal was just to produce better coverage, it would simply not make sense to label the press "fake news,"which tells people not to believe anything it reports. If, on the other hand, you want to define your own reality so that an illogical agenda seem less so...

Second, as others have described in great detail, Trump chose a phrase ("enemies of the people") replete with ominous historical resonance in other societies as a prelude to violence. As with his adoption of the slogan "America First," which emerged in the 1930s, among Nazi sympathizers averse to U.S. intervention against Hitler, it is unclear whether Trump is dog whistling dark forces in society or just stumbled into what he considers a good line. Either way, there is no reason to expect him to drop the phrase, even if he knows its origins.

Third, while every one of our previous Presidents may have criticized particular reporters, on particularly issues––Halberstam on Vietnam, Woodward and Bernstein on Watergate, Walter Pincus or Knight-Ridder on Iraq––they never publicly questioned the press as an institution.

Kennedy paid frequent homage to the First Amendment, including in a 1961 speech entitled "The President and the Press," in which he said he deliberately eschewed the word "versus," because "that is not the way I see things."

Richard Nixon's attitude toward the press was perhaps the closest to what we see today from Trump. He regularly referred to the media as "the enemy," put journalists like Mary McGrory and Daniel Schorr on his "enemies list," and did everything he could to intimidate The Washington Post into dropping the Watergate investigation (we know how that one ended). But he also saved his most biting commentary for the seclusion of the Oval Office.

While journalists many have judged George W. Bush’s Presidency harshly, helping drive his approval rating to unprecedented lows, he maintained cordial and respectful relationships with virtually all of them, whatever he may have felt about the coverage he received.

Indeed, no modern President showed anywhere near the degree of open hostility toward the press writ large that Trump displays on a near-daily basis, nor tried to enlist the public in a relentless demonization campaign.

Fox News’ Chris Wallace pressed White House Chief of Staff Reince Priebus on these points in an interview Sunday, as the White House defended the President’s comments as warranted, and urged reporters to take them seriously.

“I don't have a problem with you complaining about an individual story,” Wallace said. “But you went a lot further than that, or the President went a lot further than that. He said the fake media, not certain stories, but the fake media are enemies of the country. We don’t have a state run media in this country, that’s what they have in dictatorships.”

Priebus responded that it was not a single story the White House was concerned about, but “24 hours a day, seven days a week… talking about Russian spies, talking about the intelligence community” and other “total garbage, unsourced stuff.”

Wallace did not question how the Administration can equate adversarial coverage with somehow standing against the American people. But he did pointedly remind Priebus that “you don’t get to tell us what to do… any more than Barack Obama did.”

A fourth and perhaps most significant difference with Trump's crusade is that while journalism has always entailed risks, the world has become a far more dangerous place in which to practice it, as a privileged status in past conflicts has given way to deliberate targeting and authoritarians employ ever more coercive tactics.

The International Federation of Journalists points to steadily increasing levels of violence against media workers since it began keeping statistics in 1990. That year recorded the killing of 40 journalists worldwide. Over the last decade that number has never been under 100.

Like virtually every other journalist I know, I have friends and colleagues who paid the ultimate price to do their jobs, and I consider them no less heroic than the soldiers and diplomats who have done the same.

While he surely didn't know it, Trump tweeted at journalistic "enemies" a day after the five-year anniversary of the death in Syria of my friend Anthony Shadid, to my mind the greatest foreign correspondent of the 21st century, after a career marked by countless searing stories, and more than a few near-misses.

Intentionally or not, Trump's label also tarred people like Salih Saif Aldin, an Iraqi stringer in The Washington Post's Baghdad bureau, with whom I'd spent many sleepless nights huddled around a television set or computer screen, communicating in our broken versions of each other's languages. He was shot dead in Baghdad in the fall of 2007, conducting interviews in a part of Baghdad deemed too dangerous for American reporters to go.

I wonder whether Trump has considered the impact his statements might have on authoritarian regimes around the world that are locking up reporters at an accelerating rate.

During my time at the State Department, Secretary Kerry raised these cases, some of whom are American citizens, in literally dozens of meetings with counterparts from places like Turkey, Egypt, Iran, China and Russia. Sometimes he succeeded. Now it seems hard to imagine that such pleas, if the Trump Administration is even willing to make them, will carry anywhere near the same moral weight. And if the President of the only nation with a First Amendment can treat the press as not just his enemies, but enemies of the people he represents, there is little to stop other nations, with far fewer protections, from doing the same.

It is important to understand that being a reporter in the United States presents its own challenges. For one thing, the Washington press has the unenviable job of reporting on meetings in which they cannot participate, leaving them subject to the whims and agendas of people who can never provide the whole truth. And for a mix of reasons, including some self-inflicted wounds, journalists' approval rating in America has plummeted to around 20 percent, lower even than Trump's, which is the lowest of any new President in history.

The low regard in which they are held, and the way in which reporters were treated on Trump's presidential campaign––disparaged by the candidate, taunted and threatened by his supporters, occasionally even manhandled by his aides––had already raised legitimate, and virtually unprecedented, questions about how safe it is for American journalists to do their jobs. And that was before Trump labeled them enemies.

Wondering if I was overstating these dark scenarios, I contacted Jason Rezaian, an Iranian-American journalist for The Washington Post, who was released from an Iranian prison after being held for more than a year on trumped up charges. At the State Department, my colleagues and I had worked extensively on the negotiations that ultimately led to a prisoner exchange through which Jason was freed. I was curious, given his experiences, what he thought of Trump lashing out at his profession.

"Most of my reporting until now has been done from an authoritarian country so attacks on the American media by leaders is a phenomenon I've witnessed before. It  is absolutely not something I anticipated coming home to, though, after 18 months in prison in Iran for the crime of practicing journalism," Rezaian said.

"I worry about the new risks such anti-press attitudes, real or feigned, from this administration will create for reporters working in the US and abroad. A tense relationship between the government and the press can be a key to safeguarding core democratic values and principles, but a situation where basic notions of the other's legitimacy are being repeatedly and publicly questioned and undermined seems to me a dangerous road to start down."