It seemed like one of President Trump’s more innocuous proclamations, buried under a blizzard of devastating policy changes and mass firings: The Gulf of Mexico, he announced, would now be called the Gulf of America.

No, actually, said The Associated Press, a global news service founded in 1846. That body of water has been called the Gulf of Mexico for 400 years, and since our 4 billion daily readers around the world still use the old name, we will, too.

Trump then barred the news service from entering the Oval Office or traveling on Air Force One. As a result, a seemingly small dispute has escalated into a major test case about the role of a free press in Trump’s America.

The president’s tantrum, states Julie Pace, AP’s executive editor, “sets an alarming precedent that has the potential to affect every news outlet and, in turn, severely limit the public’s right to know what is happening inside their government.”

“We stand by The Associated Press in condemning repeated acts of retribution by this administration for editorial decisions it disagrees with,” asserted the New York Times. “Any move to limit access or impede reporters doing their jobs is at odds with the press freedoms enshrined in the Constitution.”

The Atlantic said it would stick with the Gulf of Mexico: “Our obligation is to reflect reality accurately.” But that is exactly what Trump disdains. This president, who embraced a doctrine of “alternative facts” during his first term, is now staging a war against reality, jabbing at any dedicated professional who challenges his descriptions and definitions of what is true.

Unfettered and unafraid journalists are among his prime targets, and his spear carrier Elon Musk has joined the crusade. After the CBS program “60 Minutes” aired a critical report on Trump’s first month in office, Musk trumpeted, “’60 Minutes’ are the biggest liars in the world! They engaged in deliberate deception to interfere with the last election. They deserve a long prison sentence.”

Musk’s comment about “deliberate deception” refers to a totally discredited charge that “60 Minutes” unfairly edited an interview with Kamala Harris to help her prospects. But it also reveals how far-reaching Trump’s campaign of intimidation against the media really is.

Trump has sued CBS for $20 billion over the specious allegation, and the new chairman of the Federal Communications Commission, Brendan Carr, has invited complaints against the network and threatened to hold up a pending merger between CBS’ parent company, Paramount Global, and Skydance Media.

Paramount seems eager to settle the suit, even though Trump has a weak case. Last December, ABC caved in and paid off a similar claim by Trump for similar reasons. Disney owns ABC, and like Paramount, it has vast business interests that make it vulnerable to a vengeful new president. (Disclaimer: I am a political analyst for ABC Radio.)

This week, the Washington Post, which is owned by billionaire Jeff Bezos, declined to publish an ad attacking Trump, and last fall, Bezos told the paper to withhold an endorsement of Harris.

These are some of the visible effects of Trump’s campaign to neutralize an independent press. Far more serious is the “chilling effect,” the fear and fragility he’s trying to implant in other news organizations. That impact is more insidious because it’s hidden. We’ll never know what stories are not covered, what questions are not asked, what angles are not pursued.

That’s why it’s so vital for the AP to resist Trump’s tirades, and for other news organizations to back them up.

As a nonprofit collective owned by its members, the news service is largely shielded from the pressure tactics that are working against corporate-owned outlets like CBS. Moreover, language is power, and AP has long been the leading authority over word usage and style that others follow. If AP breaks, others will, too, and a deeply dangerous precedent would be set.

“This isn’t just about the Gulf of America,” White House deputy chief of staff Taylor Budowich told Axios. “This is about AP weaponizing language through their stylebook to push a partisan worldview.”

He’s right that this fight has a much larger meaning than a name on a map. But he’s dead wrong about the rest. This is about Trump, not AP, “weaponizing language … to push a partisan worldview.” This is about the willingness of courageous journalists to resist his rages and maintain their commitment to “reflect reality accurately.”

Steven Roberts can be contacted by email at stevecokie@gmail.com.