The trial set to begin in Washington next week of Vice President Cheney’s former chief of staff, I. Lewis Libby Jr., will be the first major showdown between two competing narratives about the Bush administration’s tactics in responding to critics of the war in Iraq.

In the first version, adopted to a degree by the special prosecutor, Patrick Fitzgerald, Mr. Libby was part of a broad-ranging conspiracy to expose a longtime CIA operative, Valerie Plame, whose husband, Joseph Wilson IV, had the temerity to challenge publicly some of President Bush’s statements about Iraq’s nuclear procurement efforts. According to others, Mr. Fitzgerald is an out-of-control prosecutor who has bought into a partisan campaign to embarrass the White House and is needlessly harassing a dedicated public official who was simply trying to rebut false charges that had been leveled at his boss and the administration.

Members of both camps are seeking vindication from Mr. Libby’s impending courtroom battle, but whether they will get it is another question. The former White House official is charged with lying and obstruction of justice, not leaking, so the trial may be so circumscribed that both cheering sections are left with an unsatisfying result. What’s already clear at this juncture is that both storylines suffer from serious flaws.

The theory of a carefully concocted effort to unmask Ms. Plame hit a land mine last summer when it was disclosed that the first person to tell a reporter about her CIA connection was not Mr. Libby or the White House political aide demonized by the left, Karl Rove, but a senior State Department official skeptical about the war effort, Richard Armitage.

Some conservatives contend Mr. Fitzgerald should have shut down the probe as soon as he learned that Mr. Armitage was behind the leak that led a newspaper columnist, Robert Novak, to print the fact that Ms. Plame worked at the CIA.

“It should have meant an end to it at the very beginning,” a former prosecutor, Victoria Toensing, said. “The fact that he continued the investigation when he knew it was Armitage, it’s the disgrace of it all.”

Left-wing bloggers argue that the fact that Mr. Armitage mentioned Ms. Plame to a couple of reporters is irrelevant to the issue of whether White House officials, bent on revenge, acted separately to expose the CIA officer.

“If I come across a car with two hubcaps stolen, that doesn’t make it okay to steal the other two,” a left-wing logger and Hollywood producer who has followed the case, Jane Hamsher, said.

Ms. Hamsher also points out that Mr. Fitzgerald was not tapped to look into the case until after Justice Department officials had done a preliminary inquiry into the matter in the summer and fall of 2003. It was at that stage that FBI agents met with Mr. Libby and got answers that Mr. Fitzgerald later decided were untrue. “By the time Pat Fitzgerald took over the case, the FBI already knew that Scooter Libby had lied to them,” Ms. Hamsher said, asking if the prosecutor “was just supposed to turn his back on that?”

Mr. Libby has pleaded not guilty and his lawyers insist any misstatements he made were the product of overwork and memory problems. But, even assuming Mr. Libby did lie, Ms. Toensing questions whether what he said was material to Mr. Fitzgerald’s probe. “Fitzgerald had to have known at the outset that he wasn’t going to be able to make a case” on the leak, she said, so any misstatements were of no import.

Mr. Fitzgerald, the U.S Attorney for Chicago who was brought in to avoid conflicts of interest at the Justice Department, has been tight-lipped about his views of the case. In a press conference announcing the indictment in 2005, he argued that the laws about leaks are so arcane that prosecutors must be able to make fine judgments about motive and intent, something that is hard to do when a key player lies. “What we have when someone charges obstruction of justice, the umpire gets sand thrown in his eyes. He’s trying to figure out what happened and somebody blocked their view,” the prosecutor said. “We didn’t get the straight story, and we had to—had to take action.” Still, most leaks and most lies go unpunished, raising the question of why Mr. Libby should face any charge, even if he might technically be guilty. At the 2005 news conference, Mr. Fitzgerald seemed to dismiss suggestions that no harm was done by outing Ms. Plame and he seemed to buy into the notion that there was some ill-intentioned attempt to expose her.

“The damage wasn’t to one person. It wasn’t just Valerie Wilson. It was done to all of us,” the prosecutor said. He said CIA personnel “run a risk when they work for the CIA that something bad could happen to them, but they have to make sure that they don’t run the risk that something bad is going to happen to them from something done by their own fellow government employees.”

Mr. Fitzgerald went on to suggest that use of the perjury statute might be an acceptable way to go after a leaker, much in the way tax evasion charges were used against mobsters like Al Capone. “If you find a violation, it doesn’t really, in the end, matter what statute you use if you vindicate the interest,” he said.

Mr. Fitzgerald’s statements and his failure to act against the initial leaker, Mr. Armitage, led some to view the prosecutor as a dupe for Bush administration opponents eager for a White House scalp. “If you were against the war, it was okay to forget or to reveal details about Valerie Plame, but if you supported the war, you get indicted,” Ms. Toensing said last year. “It’s as simple as that.”

One problem with the narrative which paints Mr. Fitzgerald as a partisan zealot or a patsy for the left is that his record outside the Plame case suggests that he is anything but. He gained a reputation in the 1990s in New York as a hard-nosed prosecutor in cases stemming from the first bombing of the World Trade Center, and was credited as being among the first federal prosecutors to spot the looming threat of Islamic terrorism. After moving to Chicago, Mr. Fitzgerald kept his tough approach, irking Muslim groups by making aggressive use of material witness laws to detain suspects.

“He acts consistently from the perspective of an ultra-aggressive prosecutor,” a former prosecutor who worked with Mr. Fitzgerald in New York, Joshua Berman, said. “Anybody who layers a political filter on this is making a huge mistake….Had this been the Clinton White House, the Carter White House, or the Kennedy White House, I believe he would have approached it the same way.”

A conservative legal commentator who also worked with Mr. Fitzgerald, Andrew McCarthy, said he’s “not crazy” about the way his former colleague exercised his discretion to seek charges against Mr. Libby. However, Mr. McCarthy said a strong argument could be made that his former colleague has acted with restraint by not charging Mr. Rove or Mr. Armitage, and by not charging Mr. Libby with illegal leaking.

“An out-of-control prosecutor could easily justify bringing” more charges, Mr. McCarthy said of Mr. Fitzgerald. “The thing you don’t get past is how he treated Rove. If he wanted to ruin these guys and this administration, he’s had opportunities to do it and he’s gone about it pretty soberly.”