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.