Last week wasn’t a happy one for the Blond Goddess of television news, and this week will likely be no better. It’s never much fun when you stare at the chessboard and discover you have no more moves to make. But now that Katie Couric has moved to the CBS anchor desk and Meredith Vieira has taken over “Today,” it’s time to acknowledge the fate she has been taught to dread by the savvy strategists who have mentored her for so long and so well.

It’s checkmate for Diane Sawyer. The game is over.

What must make this development most maddening for Ms. Sawyer – both a captivating television personality and shrewd political operator – is that the game was once hers to lose. Ever since the mid-1980s, when she shot to superstardom as the first woman on “60 Minutes” and the first glamour icon in television news, it was assumed that Ms. Sawyer would one day be the first woman to anchor a network nightly newscast. Indeed, she left CBS only after it became clear that Dan Rather stood as a permanent obstacle to its anchor desk, then preeminent in the industry. Ever since, Ms. Sawyer has been searching for a way to be no. 1 again – to be the television personality everyone talks about, the magazine cover girl beloved and watched by millions.

She came close – tantalizingly close. In recent years, Ms. Sawyer owed her resurgence in popularity to a canny decision to increase her face time on television. By becoming a permanent fixture for two hours every weekday on “Good Morning America,” Ms. Sawyer re-established herself as a powerful player in the news business. That show, like NBC’s “Today,” earns hundreds of millions of dollars in profit for the network, and justifies her continued mega-million-dollar salary and considerable influence. But did a newswoman with a genuine passion for serious journalism really want to cap her career hosting an endless string of cooking segments and celebrity suck-up interviews?

The fact that Ms. Sawyer’s name surfaced several times in recent months for anchor jobs – in stories that looked suspiciously like she’d leaked them herself – made clear her true ambitions. Morning television was always meant to get her somewhere else, not to become a final resting place. Like Ms. Couric, she feels restless and ready for change. But now, in the wake of last week’s developments, the immediate prospects for Ms. Sawyer to shake up her life with a new, prominent job have evaporated.

Ms. Sawyer has a right to feel frustrated with her bosses at ABC News, who missed opportunities to restructure their news operation around her in recent months – and even to have precluded last week’s bombshell shifts. ABC News President David Westin could have moved Ms. Sawyer into the “World News Tonight” anchor chair after the death of Peter Jennings, instead of dragging his feet for months with interim fixes and eventually settling on the risky choice of Bob Woodruff and Elizabeth Vargas.

He might even have minimized the damage to “GMA” by convincing Ms. Vieira – then an ABC employee – to take Ms. Sawyer’s place; after all, it now turns out that NBC’s Jeff Zucker began wooing Ms. Vieira last October, right when Mr. Westin was wrestling with the fate of his divi sion’s future. How could he have let Ms. Vieira slip through his fingers? Now it seems likely that the appealing Ms.Vieira will preclude “GMA’s” chances of ever overtaking the “Today” show in the ratings race.

By not moving Ms. Sawyer into the anchor chair, Mr. Westin also passed up the publicity value of appointing the first female solo anchor in television history. CBS has now cleverly seized on this gambit, and Ms. Couric’s ascension has been hailed as a zeitgeist moment for women everywhere. That must be especially galling for Ms. Sawyer, whose success as a female broadcaster preceded Ms. Couric’s by a decade. While critics still debate Ms. Couric’s credentials as a serious journalist – in the wake of 15 straight years of morning television, and all its goofiness – no one would have questioned Ms. Sawyer’s readiness for the job. Unlike Ms. Couric, the recent journalism track record of Ms. Sawyer includes Emmys for prime-time investigations, and years of experience fronting serious enterprise reporting on major social issues.

How did this happen? How could a woman who has counted great military strategists among her advisers – men like President Nixon, her first employer, and a former U.N. ambassador, Richard Holbrooke, her one-time boyfriend – find herself with no place on the chessboard to move her piece? To those who follow the news business carefully, the idea of Ms. Sawyer as a casualty of war, and not a winner, comes as a cruel shock after so many years anticipating her next big move.

But of course it is way too early to count Ms. Sawyer out; she may have lost this game, but she’ll find another one she can win. For the moment, she may have been forced into retreat, but no one can reasonably expect her to disappear forever from the broadcast limelight. She remains too ambitious and too blond. She may now be forced by circumstance to consider new, game-changing career paths – a daytime talk show to rival or replace Oprah Winfrey may be one possibility. No doubt other options exist, perhaps even further outside the traditional reach of news divisions. But if Ms. Sawyer looks a little sadder than usual on “GMA” this week, give her a break. Checkmate is no fun.

dblum@nysun.com