The Air Force has decided it needs to be much more secretive since a Gazette story last month on the National Space Defense Center in Colorado Springs triggered a public relations “stand down.”

In an email, the Pentagon confirmed the existence of a memo that bans most Air Force public relations worldwide until airmen are trained on operational security.

“In line with the new national defense strategy, the Air Force must hone its culture of engagement to include a heightened focus on sound operational security,” says the memo, obtained by The Gazette.

A PowerPoint presentation sent out after the memo cited The Gazette’s story as one that “inadvertently identified a national center of gravity to adversaries.”

Yet the military has publicly acknowledged for three years the existence of the space defense center at Schriever Air Force Base and its relationship with spy agencies, including the National Reconnaissance Office. Top Pentagon officials have cited the center as being at the heart of American efforts to defend military satellites.

It remains unclear why The Gazette story contributed to the stand down.

The story, one of three cited as a reason to cease media outreach, was driven by an Air Force news release that highlighted how the space defense center was entering a new phase with 24-hour operations.

The story was arranged through the Air Force Space Command public affairs office, and the single interview with the center’s Col. Todd Brost was conducted in the presence of a public relations expert from the command.

In the wake of the story, which focused on the center’s partnership between airmen and intelligence agency experts to protect military satellites, the Air Force has banned media visits to bases without Pentagon approval, the memo said.

“Our units are going through operational security training so we’ve limited some engagements until the training is complete,” Air Force spokeswoman Ann Stefanek said Tuesday in an email from the Pentagon. “As units finish their training, they are being cleared to continue engagements and base visits. Many have already done so. In the meantime, all units are responding to questions.”

The Washington D.C.-based Military Reporters and Editors Association reacted with alarm to the Air Force move.

“We worry that the definition of the kind of unclassified information that can be withheld is subjective,” association president John M. Donnelly said in a statement. “Given the ambiguity about what’s allowed and the message from the top stressing secrecy, officials who are wary about their careers may err on the side of withholding information.”

Security classes for Air Force public relations workers have started, and a wider effort is aimed at a “culture shift” toward increased secrecy, according to documents obtained by The Gazette. It’s unclear when the service will resume normal public relations efforts.

The service said the secrecy is needed as the country confronts growing military might in Russia and China.

“The security environment has shifted from an unconventional threat to great power competition,” documents say.

While the Air Force wants more secrecy, the Pentagon is sticking by its pledges of increased transparency that have come under Trump administration Defense Secretary James Mattis.

“We remain committed to being as open and responsive as possible to the media and the American public while protecting operational security,” said Stefanek, the Air Force’s chief of media relations, in an email.