It’s week one of the Trump presidency and the White House is already at war with the media, touching off panic about the end of the republic and the death of facts.

The worries are exaggerated — or, at least, premature.

There’s nothing new about politicians hating the press; presidents and their aides have been at odds with the media for at least half a century.

Richard Nixon put journalists on his enemies list and ordered the Internal Revenue Service to audit them. Ronald Reagan’s press secretary blacklisted critical reporters. Bill Clinton’s aides lied about matters of state, even as Clinton lied about matters of the flesh. Barack Obama’sWhite House threatened to prosecute reporters over leaks.

Administrations and the press are destined to be at cross purposes. That’s not merely normal; that’s healthy. The media’s highest purpose is to act as a watchdog, not a cheerleader.

And it’s not as if President Trump is cutting off media access entirely. He still wants to use the media for his own purposes — as he did, to great effect, during the campaign.

His press secretary is holding regular briefings in the White House. The president granted a long, exclusive interview this week to ABC News, a pillar of the mainstream. Trump adviser Kellyanne Conway said he may even hold cozy dinners with selected reporters when First Lady Melania Trump is in New York.

Relationships between politicians and reporters are almost entirely transactional, and always have been, even in the bad old days when reporters and politicians went out drinking after hours.

Presidents and their aides don’t talk to reporters because they yearn to be held accountable (they don’t). They do it to promote their political agendas.

What’s different this time is the president’s in-your-face style. Reporters “are among the most dishonest people on Earth,” he said (again) last week.

Other presidents tried, most of the time, to keep their irritation about press coverage private; Trump flaunts his in public.

And this president, more than any in memory, feels unconstrained by the distinction between truth and falsehood. He utters self-aggrandizing fictions and gets angry when fact-checkers show them to be nonsense.

He was at it again this week, raging about the record crowd at his inauguration (it wasn’t) and insisting he would have won the popular vote but for millions of illegal voters (there’s no evidence to support that claim).

At times, Trump and his aides appear bent on delegitimizing not merely the media, but the concept of verifiable facts.

“There’s no way to quantify crowd numbers,” Conway said Sunday, incorrectly. The White House, she said, had simply provided “alternative facts.”

But Trump’s style is precisely why there’s no need — at this point — to worry about the end of civilization: It’s not helping him crush the 1st Amendment, it’s just getting in his way.

The new president actually made a pretty good start this week. His cabinet nominees appear to be sailing to confirmation, even the most controversial ones. He signed executive orders to begin dismantling Obamacare and withdraw from a Pacific Rim trade pact. He jawboned automobile executives to stop moving jobs overseas, always a crowd-pleasing move.

And what was the dominant story? The president’s apparent obsession with secondary issues like crowd counts and voting tallies.

More important, he’s impeached his own credibility (already low) and that of his new press secretary, Sean Spicer (who arrived with a reputation for honesty). That’s a handicap that can’t be erased.

Lyndon B. Johnson took two years to earn a reputation for a “credibility gap.” Trump did it in a weekend.

On Tuesday, The New York Times used the word “lie” to describe his claim about illegal voters. That’s not a win for any president.

These early battles aren’t pretty, but they have had a healthy, bracing effect on the media, not a numbing one. Instead of devaluing fact-checking, the new Trump administration has just made it more central to what the media do, and more necessary to the public.

True believers in Trump may rally to alternative facts, but most Americans will believe their own eyes.

Already, as media economist Ken Doctor has reported, paid circulation at major newspapers is growing, and contributions to journalism nonprofits like ProPublica have spiked.

Equally important, these collisions have made it clearer than ever that “access journalism” is rarely as valuable as investigative journalism.

White House reporters should ignore proposals that they boycott briefings or refuse to interview presidential aides. That’s silly. But they’ve been put on notice that those briefings and interviews are unlikely to be as useful as talking to midlevel bureaucrats who are already yearning to leak.

“The answer,” Martin Baron, editor of the Washington Post, said recently, “is pretty simple. Just do our job. Do it as it’s supposed to be done. The public expects that of us. If we fail to pursue the truth and to tell it unflinchingly … the public will not forgive us.”

Serious, solid journalism is coming back into fashion. As long as we remember to practice it.