Graydon Carter’s decision to retire after a quarter century as Vanity Fair’s top editor—reported Thursday by The New York Times—was prompted in part by an inescapable truth: Wintour is coming.

Anna Wintour, the doyenne of Vogue and artistic director of Conde Nast, nominally supervises the publishing company’s 15 glossy print magazines, but has generally not attempted to exercise authority over Carter’s Vanity Fair or David Remnick’s New Yorker.

A year ago, however, Carter fought tooth-and-nail against a corporate restructuring plan, promoted by Wintour and other Conde Nast execs, for Vanity Fair to lose its designated creative director and fact-checkers, along with those of the other magazines, in order to consolidate them all into company-wide departments as a cost-saving measure.

“It all kind of came to a head last fall, and Graydon was pissed off about that,” said a Vanity Fair insider who spoke on condition of not being further identified. “It was an Anna project—she was invested in it—and that was seen as a real affront.”

Wintour, through a company spokesperson, declined to comment on the incident—as did Carter.

A favorite of Conde Nast owner and chairman Si Newhouse—who quietly gave up the reins at age 84 in 2012—Carter still had sufficient muscle inside the company to win the restructuring battle and arrange for Vanity Fair to be exempted; he celebrated with his cheering staff on the 41st floor of Conde Nast’s One World Trade Center headquarters in Lower Manhattan.

“When Graydon wakes up to an issue, he really can still bring a lot of political clout, both inside and outside of Conde Nast,” said the Vanity Fair insider. “The people at Conde Nast corporate realize how damaging it would be to alienate someone like Graydon, who has a lot of friends” high up in the media and entertainment industries, whose goodwill Conde Nast understandably values. “A lot of his power comes from all those relationships.”

But friends of the 68-year-old Carter, along with insiders at Vanity Fair and Conde Nast, say he has increasingly come to grips with the reality that future internal victories are unlikely as the once-profitable magazine publishing industry continues to struggle financially in the digital age.

If Carter were to stay on past December, when he plans to leave his exalted position, he would undoubtedly have been forced to preside over the sort of massive bloodletting that Vanity Fair had previously dodged under his leadership.

His as-yet unnamed successor as editor in chief—whether it be the Hollywood Reporter’s Janice Min or New York magazine’s Adam Moss, two names in the industry gossip mill, or some other brave soul—is unlikely to enjoy Carter’s level of editorial independence from Wintour, or Carter’s protection from major budget cutting.

“The last couple of years for Graydon have not been as much fun as most of his tenure there,” said a Carter pal. “It has to do with doing more with less, and Conde Nast has been undergoing continual restructuring of sorts.”

This friend added: “Graydon is very, very devoted to the staff—unlike many other editors. Graydon finds it very, very difficult to let anyone go. It’s just very hard for him, and he didn’t want to be in the situation where he has to let people go any more than he has already done.”

Still, a Conde Nast insider pointed out that Vanity Fair, under Carter, has suffered far less than some of the company’s other glossy titles. And the company, over all, is in better shape than, say, Time Inc., the former magazine division of Time Warner which has cinched its corporate belt ever tighter since it was spun off into a separate entity in 2014.

“Conde Nast,” said Carter’s friend, “is a Mercedes Benz compared to the jalopy of Time Inc.”

Meanwhile, Carter has been seen in some quarters of Conde Nast as a privileged character.

“Graydon has run his own shop, and has been allowed to run his own shop, and has really done virtually nothing in terms of trimming costs,” said this Conde Nast insider, notwithstanding that Vanity Fair, like the other magazines, has experienced layoffs over the past eight years. “Vanity Fair is an amazing title, but it’s incredibly expensive—and where everyone else has been trying to do their part [to economize], it hasn’t happened so much with Graydon.”

Yet, in a lengthy and effusive company-wide email Friday, Conde Nast chief executive Bob Sauerberg heaped laurels on Carter—“the iconic, innovative, and truly incomparable leader of Vanity Fair.” Sauerberg went on: “In light of all that Graydon has accomplished at Vanity Fair, to say thank you seems somehow insufficient to the moment.”

Calling Carter’s hiring in 1992 “a characteristic stroke of genius by Si Newhouse,” Sauerberg added: “Graydon has also built a strong foundation for the future and continued success at Vanity Fair.”

Meanwhile, in a valedictory essay posted on Vanity Fair’s web site, Carter saw himself likened to the New Yorker’s Harold Ross, Esquire’s Harold Hayes and Cosmopolitan’s Helen Gurley Brown among other magazine legends.

“I think he’s gotten out with total class here—it was a well-executed exit,” said Carter’s friend, media pioneer Tom Freston, the co-founder of MTV and former chief executive of Viacom. “He’s leaving on top, wishing that things were doing better. The magazine business is clearly going through some tumultuous times, and one could argue that the heyday is over.”