WASHINGTON - I. Lewis "Scooter" Libby was "put through the meat grinder" by the White House shortly after the Iraq war began, scapegoated to conceal that top presidential adviser Karl Rove helped disclose an undercover CIA officer's identity, a defense attorney contended yesterday as Libby's perjury trial began.

The attorney, Theodore Wells, and special prosecutor Patrick Fitzgerald agreed that Vice President Cheney had ordered Libby, then his chief of staff, to contact reporters early in the summer of 2003 in an effort to rebut criticism that the administration had selectively used intelligence to justify the invasion of Iraq.

According to Wells, the confidential conversations Libby had with several well-known journalists were not intended to spread the identity of Valerie Plame Wilson, the covert CIA officer. Instead, Libby's lawyer said, he was acting at Cheney's instructions to respond to allegations that the vice president had withheld information that would have raised doubts about whether Iraq was trying to develop weapons of mass destruction.

The dramatic opening statements laid bare fissures deep inside the White House. They came as the prosecution and defense provided to the jury crackling portrayals of their opposing theories of the case.

The two sides' accounts exposed jurors to handwritten notes by Cheney, the internal culture of major newsrooms, a tape recording of Libby speaking to grand jurors, and a White House under fire as its justification for war was beginning to unravel.

Libby, 56, is accused of five felony charges stemming from a federal investigation into the leak of Valerie Wilson's identity to the media. Libby is not charged with the leak itself, nor is anyone else. He faces two counts of making false statements to FBI agents, two counts of perjuring himself before a grand jury and one count of obstructing the investigation, and has pleaded not guilty to all charges.

"How could we reach a point where the chief of staff for the vice president was repeatedly lying to federal investigators?" Fitzgerald asked jurors rhetorically. "That's what this case is all about."

During an hour-long opening statement, the prosecutor described what he called "a firestorm" inside the White House on the final day of the July 4, 2003, holiday weekend, when an op-ed piece by Wilson's husband, former Ambassador Joseph Wilson, attacked the administration. Joseph Wilson, whom the CIA had sent to Niger to determine whether Iraq sought uranium there for its nuclear-weapons program, said Bush and his aides "may have twisted the intelligence" on whether Iraq was seeking weapons of mass destruction.

Libby told investigators he was surprised to learn from NBC's Tim Russert in July 2003 that Joseph Wilson was married to Valerie Plame. But Fitzgerald contended that Libby, at Cheney's direction, had been asking people about Wilson for weeks.

The prosecutor said Libby's assertion to a grand jury that he simply had forgotten what he knew was implausible, because he had passed on Valerie Wilson's name to reporters and then-White House press secretary Ari Fleischer before he ever spoke with Russert.

"You can't learn something startling on Thursday that you're giving out Monday and Tuesday of the same week," Fitzgerald said.

Wells countered that "this is a weak, paper-thin, circumstantial evidence case about he-said, she-said."

The defense attorney asserted that Libby had given investigators his "good-faith recollection" and that any mistakes in his memory were innocent. He also contended that the journalists and administration officials who are to testify also have imperfect memories. He said that Libby did not know Valerie Wilson worked in a covert role, and had no motive to lie to investigators.

According to Wells, when the federal investigation of the leak began in the fall of 2003, Libby was not worried about his job, but was "concerned about . . . being scapegoated." Scott McClellan, then the new White House press secretary, said publicly that Rove was not responsible for any leaks, Wells said, but did not say the same about Libby.

Libby, Wells said, told Cheney he feared that "people in the White House are trying to set me up." Wells then showed the jury the text of a note Cheney had jotted that said, "Not going to protect one staffer [plus] sacrifice the guy that was asked to stick his neck in the meat grinder because of the incompetence of others."

"That one person was Karl Rove," Wells said. "He was viewed as a political genius. . . . He had to be protected. The person who was to be sacrificed was Scooter Libby." According to Wells, the vice president tried, unsuccessfully, to persuade White House colleagues to publicly clear Libby as the source of the leak.

Valerie Wilson's identity first became public in a July 14, 2003, column by Robert Novak. Rove and Richard Armitage, then the deputy secretary of state, have acknowledged being Novak's sources.

Wells said the "meat grinder" Libby was put through meant he took on the extra task of having brief conversations with reporters while carrying out his "day job" dealing with crucial national security matters.

Later yesterday, the prosecution's first witness, Marc Grossman, a former undersecretary of state, testified that Libby asked him in May 2003 to look into Joseph Wilson's trip to Niger. Grossman said he spoke to Wilson and learned that his wife worked at the CIA and had appeared to help arrange the trip.

"I thought the whole business was of less-than-zero importance," Grossman testified.