Last Wednesday, Rather launched a "60 Minutes" pre-emptive strike against the president. Rather's charges: Bush got into the National Guard through pull, was an insubordinate officer who refused to take the medical exam to keep flying and used clout to prevent his being disciplined.

Rather's attack was based on four newly discovered memos said to be from the personal files of Bush's squadron commander, Lt. Col. Jerry B. Killian. The memos, writes The New York Times, indicate "Mr. Bush ... failed to take a physical examination 'as ordered' and that his commander felt under pressure to 'sugarcoat' his performance rating, because First Lieutenant Bush ... was 'talking to someone upstairs.'"

Rather seemed to have substantiated the rumors about Bush's Guard service, as his piece also featured an interview with former Lt. Gov. Ben Barnes, who confessed to having interceded to get Bush into the Texas Air National Guard.

Within hours, however, Rather's case was crumbling. From both independent analysis of the memos and witness testimony, it appears that Rather may have been duped into colluding with a scheme to use forgeries to smear and sink a president of the United States.

First, the new Killian memos appear to have been produced on a word processor that did not exist in 1972-73. They are written in a Times New Roman typeface rarely found on old typewriters. The letters "th" in "111th squadron" are written in a "superscript" few typewriters of the Vietnam era had. And the spacing of the letters on the memos is more like that of modern word processors than of early 1970s' typewriters, where letters were of equal size.

Killian's widow (he died in 1984) and son say he never kept notes and call the memos a farce. "No officer in his right mind would write a memo like that," says Killian's son Gary, an ex-Guardsman himself, of the memo in which Col. Killian says he is being pressured to "sugarcoat" Bush's record of insubordination.

Rufus Martin, personnel chief in Killian's unit, also calls the memos fakes: "I don't think Killian would do that, and I knew him for 17 years."

On "60 Minutes," Rather identified the senior officer who was said to be leaning on Killian. "Killian says (in his memo) Col. Buck Staudt, the man in charge of the Texas Air National Guard, is putting pressure on to 'sugarcoat' an evaluation of Lt. Bush." But according to The Dallas Morning News, Staudt was discharged from the Guard and gone 18 months before Killian's memo was written.

Rather claims Maj. Gen. Bobby Hodges, Col. Killian's superior, confirmed to CBS that the memos were consistent with what he recalls.

But ABC quotes Hodges as saying CBS mislead him into thinking the memos were handwritten, and he thus responded, "Well if he wrote them that's what he felt." Hodges now calls the memos a "fraud" that has been "computer-generated."

If Killian did write the four memos, notes National Review's Byron York, he would have to have been a complete hypocrite. For as he was allegedly writing bitter memos to himself about Bush, he was praising Lt. Bush in the official records in Guard files. Killian's widow says her late husband was an admirer of young George.

As for Ben Barnes, his daughter Amy says her father is now lying. Barnes is a Kerry fund-raiser and Nantucket neighbor of the windsurfer whose story about intervening for Bush has changed over the years.

Despite the cloud over the authenticity of the memos, CBS says it is conducting no internal investigation of how it got them or whether they are authentic. Hard to believe. For the reputations of Rather, CBS and "60 Minutes" are all on the line.

It should not be difficult to authenticate the memos. If they were written by Killian over an 18-month period, then other memos about unrelated matters, but with the same Times New Roman font, the same spacing, the same signature and the same "superscript" should be there. If, however, none are found, CBS may have placed its credibility behind a criminal forgery to destroy a president.

Indeed, if these memos turn out to be fakes, CBS and Rather will be guilty of, at least, having been played for fools. At worst, they could be convicted in the court of public opinion of collusion in a plot to bring down a president -- a plot into which they were lured by a blinding bias against George W. Bush.