The legal case against I. Lewis Libby: how strong?

What the judge allows the jury to hear will be critical to the outcome of the case, say legal analysts.

When Special Counsel Patrick Fitzgerald began his investigation in December 2003, his instructions were to identify who leaked the name of a CIA agent to columnist Robert Novak and determine whether that action violated any secrecy laws.

Nearly two years later, the answer to that question appears to be that no secrecy laws were clearly and intentionally violated. But along the way to attempting to discover the truth about the original leak, Mr. Fitzgerald encountered a senior White House official who he says attempted to obstruct his investigation.

Now, with the prospect of a long-drawn-out, and politically charged trial in Washington, a new question emerges:

Why would I. Lewis Libby, who resigned Friday as Vice President Cheney's chief of staff, risk prison to thwart a special counsel's investigation?

"There is an innocent explanation and a nefarious explanation," says Paul Rothstein, a law professor at Georgetown University.

The nefarious explanation is that Mr. Libby and other White House insiders intentionally leaked the identity of a CIA agent to punish her husband for his public criticism of the administration's Iraq policies, Professor Rothstein says. Under this theory, Libby's alleged misstatements to FBI agents and the grand jury were designed to prevent investigators from learning who else at the White House was involved in what would amount to a criminal conspiracy to disclose national security secrets to discredit a critic.

The more innocent explanation is that Libby's alleged misstatements - "assuming they were intentional" - were aimed at heading off political embarrassment, rather than covering up criminality. "He knew it would be embarrassing politically if the government even accidentally and innocently was the source of [the leak of the agent's name]," Rothstein says.

Many are likely to embrace the nefarious explanation, he adds, but the actions of the special counsel in declining to charge anyone with illegally disclosing secrets suggest the innocent explanation may be closer to the truth.

Joseph diGenova, a Washington lawyer and former US attorney, says one of the first battles defense attorneys are likely to wage is to attempt to purge the indictment of any references to classified information.

"There is going to be a ferocious battle over the contours of what the jury actually gets to hear in this case," he says.

The five-count indictment against Libby charges that he lied to investigators and the grand jury about how he learned the identity and employment of the CIA agent whose name was leaked to the press. Libby said he learned that information from reporters. Mr. Fitzgerald said his investigation showed that Libby had learned those facts much earlier from individuals within the government.

While the indictment discusses the importance of classified information and keeping secrets, the prosecutor did not charge Libby with violating any laws related to classified information. "The prosecutor is trying to have it both ways. He can't prove a violation [of national security] but he's trying to allege one," Mr. diGenova says.

"A trial judge is going to balance that and could very well strike that language [dealing with classified information]," he says. "When [Fitzgerald] loses that language, he loses all kinds of power in the charging document."

DiGenova adds that if the trial judge allows the references to classified information to remain in the indictment, defense lawyers will probably attack the CIA itself for failing to take the necessary measures to protect its own agent.

It was the CIA that enlisted the agent's husband, Joseph Wilson, for the sensitive mission in Africa, and it was the CIA that permitted Mr. Wilson to publicly disclose his role and publicly criticize the White House in an op-ed piece in The New York Times, diGenova says. In effect, the CIA set the stage through sloppy tradecraft for the disclosure of one of its agents.

Witnesses will also play a key role at the trial, analysts say.

"You never know how a jury is going to evaluate the credibility of the witnesses," says Paul Butler, a law professor at George Washington University and a former federal prosecutor. The central witnesses in Libby's case will probably be news reporters, who may appear reluctantly on the stand or who may demonstrate sympathy toward their former source.

DiGenova says perhaps Libby's best defense will be the simplest defense - that he had no intention of lying.

Rothstein says the Libby case raises questions about the fairness of appointing a special counsel to engage in open-ended investigations that involve political officials in Washington.

He says political officials are under more pressure than most other Americans faced with a criminal investigation. "Because they are afraid of political embarrassment ... they can't do what normal people would do in this situation and simply take the Fifth - plead the privilege against self-incrimination and not answer," Rothstein says. "They take a big political hit for that, so they lie," he says.

Rothstein says to avoid this kind of trap, special prosecutors should use their prosecutorial discretion not to file coverup charges when there is no evidence related to the alleged underlying crime.