After two weeks of crisis, the outward calm that has settled over CBS News, the network and its affiliates promises to be short and fragile.

It will last until results of an investigation into the inclusion of apparently bogus documents in a Sept. 8 “60 Minutes” story about President Bush’s performance in the Texas Air National Guard are submitted to CBS-or until another outbreak of finger-pointing and backbiting within CBS News.

Since all the big bombshells appear to have been revealed, albeit not resolved, during the press and political feeding frenzy, some close observers are hoping that the investigation could be concluded, written up and submitted to CBS News President Andrew Heyward and Viacom Co-President and Co-Chief Operating Officer Leslie Moonves in perhaps three weeks.

In the meantime, debates will ensue over the fates of anchor Dan Rather and producer Mary Mapes, and affiliates will continue to do damage control locally.

Richard Thornburgh, the attorney general during the Reagan and first Bush administrations and sometime critic of CBS News, and Louis Boccardi, retired president of the Associated Press, have begun their work as leaders of the inquiry at an undisclosed location.

The two men held their first session last Thursday, the day after they were named to do an independent probe of the story that was reported by Mr. Rather, produced by Ms. Mapes and rushed onto the lineup of the first broadcast of Josh Howard’s tenure as executive producer of the Wednesday edition of “60 Minutes.”

The critics are already attacking CBS News for what is seen as its slow response to reports by bloggers, some newspapers and other networks, which came out as soon as the story aired on “60 Minutes.” They charge that CBS’s failure to act promptly is what has caused it to become a full-blown journalism and identity crisis for the network.

There will be debate over whether the colloquial and controversial Mr. Rather, 72, will be forced as a result of the situation to retire or take up another role before his contract ends at the end of 2006. The question is complicated by years of indecision at CBS News on the question of who will be Mr. Rather’s successor as anchor of “CBS Evening News.” There will also be added pressure from Mr. Rather’s longtime critics, including some conservatives, who have used this to fire up new attacks on the newsman.

“Until the review is in, all questions are rhetorical,” said one veteran of network news circles.

That comment was made before CBS News announced late Friday afternoon that Mr. Rather will anchor 90 minutes of network coverage of the first of three debates between President Bush and challenger John Kerry at 8 p.m. Thursday on the campus of the University of Miami.

The announcement, perhaps signaling a business-as-usual attitude at CBS News right now, could help stifle questions about whether Mr. Rather will wind up anchoring election night coverage should he be cleared in this matter. By the Nov. 2 election, Mr. Rather could be absolved of significant responsibility in the document story, since he was in Florida covering Hurricane Frances while Ms. Mapes was obtaining the contested memos through still-murky channels.

Such an absolution depends, however, on whether Mr. Rather-who is known to embrace a hands-on approach to his work-is able to live with what some call a “Peter Arnett defense.” (Mr. Arnett claimed that he essentially only read a script written by someone else for the 1998 Tailwind story that ranks as CNN’s journalistic low point.)

However, on some points, the verdict is in outside CBS.