WASHINGTON -- By his own account, I. Lewis "Scooter" Libby was a very busy man on July 10, 2003.
That day, according to his calendar, he had a senior staff meeting; an intelligence briefing with his boss, Vice President Dick Cheney; a CIA briefing; and lunch with Cheney and then-House Speaker Dennis Hastert of Illinois.
He was reviewing more than a dozen terrorist threats and checking up on trouble spots around the globe, such as North Korea's escalating plans for developing nuclear weapons.
Libby had also been busy talking with reporters about a CIA operative who was married to an emerging critic of the Bush administration's march to war in Iraq. On that day in July, he had one such conversation, with Tim Russert of NBC News.
Libby goes on trial in U.S. District Court today, charged with lying to a grand jury about the conversations he had with Russert and other reporters and, in the process, obstructing a federal investigation.
His defense is a novel one: that he was so preoccupied with life-or- death affairs of state that it affected his ability to accurately recall events for federal investigators.
Prosecutors have a simpler explanation: He lied.
The "faulty memory defense," as U.S. District Judge Reggie B. Walton has called it, is just one intriguing aspect of what promises to be one of the more remarkable trials in Washington in years.
Expected to last six weeks, the trial is likely to provide a glimpse into how the White House responded to critics of its Iraq war policies. It will include testimony from Cheney, marking the first time that a sitting vice president has appeared as a witness in a criminal prosecution.
The politically charged case against Libby might be the closest thing that critics of the Bush administration ever get to a public trial dealing with the justifications for the Iraq war.
While Walton has made it clear that he intends to keep the case narrowly focused on questions of whether Libby lied, legal experts say it might be difficult for jurors to leave behind their feelings about the war.
"In most cases, politics are irrelevant. But this case is political," said Carolyn Koch, a Fairfax, Va., jury consultant. "People are so inflamed about the war in Iraq, and here they have a target in front of them. It is an opportunity to vent some anger."
The trial is the culmination of a three-year investigation that began with a July 14, 2003, article by syndicated columnist Robert Novak.
Novak took on former envoy Joseph C. Wilson IV, who had just written an op-ed piece in The New York Times that cast doubt over Bush's assertion in his 2003 State of the Union address that Saddam Hussein was seeking to acquire weapons-grade uranium from Niger. The CIA had sent Wilson to Niger in February 2002 to evaluate reports of sales of nuclear material. Novak suggested in his column that the trip was based on nepotism. Citing administration sources, he wrote that Wilson's wife, Valerie Plame, worked at the CIA on weapons of mass destruction issues.
In December 2003, the Justice Department appointed U.S. Attorney Patrick Fitzgerald in Chicago as special counsel to investigate whether laws making it a crime to divulge the status of a covert operative were broken.
Fitzgerald turned up evidence that the White House was greatly concerned about Wilson. The prosecutor also obtained evidence that other officials, including White House political director Karl Rove, had discussed Plame with journalists before her name was published.
But Fitzgerald never charged anyone with breaking the law that protects covert agents. And he continued to investigate even after learning early on who had leaked Plame's identity to Novak. That person, former Deputy Secretary of State Richard L. Armitage, was not charged.
Libby was indicted in October 2005 on charges that he lied under oath about his conversations with three reporters concerning Plame. In testimony, he had acknowledged talking with the reporters about Plame, but said he was passing along tips he had heard from other reporters, including Russert.
But the journalists, including Russert, testified that it was Libby who told them about Plame. And Fitzgerald turned up evidence that Libby was assiduously gathering information about Wilson and Plame and that he learned her identity through a number of sources, including Cheney.
The government is expected to call the reporters, Time magazine's former White House correspondent Matthew Cooper, former New York Times reporter Judith Miller and Russert.
Libby is expected to call other journalists with whom he spoke during that period to show that he did not disclose information about Plame to them.
He is also expected to challenge the testimony of Cooper and Miller. Each had initially resisted cooperating with Fitzgerald in talking about conversations they had with Libby because they considered him a confidential source they wanted to protect. Miller spent 85 days in jail for contempt before cooperating.
But mainly, Libby is betting on what one lawyer calls his "busy man defense."
The defense is unusual because Libby is in essence admitting that he might not have told the truth, which lawyers said is a risky gambit in perjury cases, where defendants usually argue that what they said was technically true or that they were confused by the questions posed to them. They said they could not recall another case where it had been tried in court.
Jeffrey Frederick, a Charlottesville, Va., jury consultant, said the test for Fitzgerald would be showing that the conversations with journalists dealt with a subject that was so important that a reasonable person would have remembered it. That could be tough for Libby to overcome because the subject matter was the war and Wilson - whom the White House clearly had concerns about.
"We are not talking about whether you had tuna or sirloin on a Friday night," Frederick said.
Richard B. Schmitt writes for the Los Angeles Times.