This trend story has been running for a generation. The latest salvo -- Leslie Bennetts' book "The Feminine Mistake," a call-to-work warning women about the long-term costs of staying at home -- set off another round of news stories and cyberspace debates about the battlefront.

But I've got news for you: This is a war that isn't.

The ballyhooed Mommy Wars exist mainly in the minds -- and the marketing machines -- of the media and publishing industry, which have been churning out mom vs. mom news flashes since, believe it or not, the 1950s. All while the number of working mothers has been rising.

Here are the facts: Since 2000, the percentage of working mothers with infants has held steady at 53.5 percent, according to a February report from the Bureau of Labor Statistics. When they can afford it, married women with infants take maternity leaves of a year or so, but then head steadily back to work: 75 percent of mothers with school-age children are on the job. Most work because they have to. And most of their stay-at-home peers don't hold it against them.

But that doesn't stop the media machine. Whether or not William Randolph Hearst ever really said "You supply the pictures, I'll supply the war," everyone knows a war is good for the news business. The Mommy Wars sell newspapers, magazines, TV shows and radio broadcasts, as mothers everywhere seize on the subject and agonize.

That's because middle- and upper-middle-class women are a demographic that responds well to anxiety, says Caryl Rivers, author of "Selling Anxiety: How the News Media Scare Women." She sees the Mommy Wars as "the intellectual version of 'Thin Thighs in 30 Days.'" Tell women that working will damage their marriages, health and children and they will buy your magazine, click on your Web site, blog about your episode and write letters to the editor. If your goal is to increase your hit rate or impress your editor with something that's widely discussed, there's no downside.

All the above was accomplished by some of the most notorious Mommy Wars articles, which, in recent years, have appeared in the elite triumvirate of the New York Times, the Atlantic and the New Yorker. That list includes "The Opt-Out Revolution" by Lisa Belkin, a 2003 Times Magazine cover story that looked at a handful of Princeton grads who (unlike most of their peers) left demanding jobs to stay home with their children; Caitlin Flanagan's gloating potshots at working moms, especially "How Serfdom Saved the Women's Movement" in the Atlantic in March 2004 and "To Hell with All That" in the New Yorker in July 2004; and a Sept. 20, 2005, front-page article in the New York Times that repeated that many women at elite colleges were opting for motherhood over careers.

All garnered enormous buzz. Belkin's piece was the most e-mailed Times article of the year, drawing so many letters that the Times ran them for four weeks. The article was critiqued on almost every prominent media Web site and online opinion magazine, clearly a resounding marketing success.

The New York Times is tugging at the guilt of the privileged -- and has been for more than half a century, with "career women go home" articles dating to 1953. But the less affluent are just as heavily targeted. In a November 2003 "Dr. Phil" show, working moms and stay-at-home moms were seated on opposite sides of the aisle and encouraged to hurl insults across the divide. The show's Web site drew 152 pages of comments and a joint statement of disapproval from its two featured experts (who insisted that their thoughtful discussion was misleadingly edited to look like a fight) -- and the show is still being talked about.

Consider the Jan. 23 "Oprah" show, called "My Baby or My Job: Why Elizabeth Vargas Stepped Down." The show attracted nearly 1,500 Web messages despite its flatly false premise, as Vargas still has an impressive job, even if it's anchoring "20/20" instead of the ABC evening news. Or take Leslie Morgan Steiner's 2006 book of essays by mothers, a volume she edited explicitly to bridge misunderstandings between mothers at home and those at work. Over her objections, Random House titled the book "Mommy Wars: Stay-at-Home and Career Moms Face Off on Their Choices, Their Lives, Their Families." Can you say "inflammatory"?