WASHINGTON -- The Navy attorney assigned to represent a Guantanamo prisoner facing war crimes charges before a military commission is confronting a dilemma: How to proceed now that the case has been injected into the Supreme Court nomination battle?

A three-judge appeals court panel last month rejected Lt. Cmdr. Charles Swift's challenge to the commission's legality. One of the judges was John Roberts, who in April heard arguments about the Bush administration's policy as he was discussing a Supreme Court appointment in private conversations with the White House. On July 15, when Judge Roberts met with President Bush for the job-clinching interview, he joined a ruling in favor of the defendants, who included Mr. Bush.

When Judge Roberts disclosed that sequence of events this month in response to a confirmation questionnaire from the Senate Judiciary Committee, a number of legal ethicists suggested that he should have recused himself from the case. Barring that, they say he should have at least notified Cmdr. Swift of his dealings with the White House so the lawyer could consider any possible prejudice to his client. A circuit court judge can recuse himself or herself from a case without explaining the reason why.

Now, Cmdr. Swift has until Sept. 2 to decide whether to file a formal challenge to Judge Roberts's participation in the case with the U.S. Court of Appeals for the District of Columbia Circuit where Judge Roberts has served for two years. Judge Roberts remains on the panel considering Cmdr. Swift's motion to stay its ruling while the Supreme Court decides whether to hear an appeal. Cmdr. Swift declined to comment for this article.

A challenge to Judge Roberts's participation could bring a new hearing or, if a stay isn't granted, at least delay the start of proceedings against Cmdr. Swift's client, Salim Hamdan, that the government intends to restart at Guantanamo. Mr. Hamdan, a Yemeni captured in Afghanistan after the U.S. invasion in 2001, admits to serving as Osama bin Laden's driver, but denies terrorism charges.

For Cmdr. Swift, challenging Judge Roberts's ethics invites charges of aiding the administration's political opponents. But remaining silent could suggest Cmdr. Swift is pulling his punches.

"From the perspective of the attorney, his primary focus should be the interest of his client," says Harvey Rishikof, a professor of national-security law at the National War College in Washington. "The calculation for Cmdr. Swift is, if he gets a rehearing from the circuit court, will he get a different set of judges who would be more sympathetic to his client's position? Since he lost on everything, the only question, if he loses again is, could he lose on better reasoning?"

Complicating matters is Mr. Hamdan's appeal petition lodged with the Supreme Court, which will consider whether to hear the case when it meets Sept. 26.

Then there is the question of what Judge Roberts, if confirmed, would do. Traditionally, Supreme Court justices recuse themselves from cases where they previously sat in judgment. But they determine their own ethical responsibilities, so the final call would be up to him

There is no evidence that the July 15 ruling would have been different without Judge Roberts -- or if he never had been considered for the Supreme Court. The panel unanimously reversed a lower court that found that Mr. Bush exceeded his authority by creating military commissions that don't afford defendants the rights guaranteed by the Constitution or the Geneva Conventions.

But in an article published last week in the online magazine Slate, three law professors cited prior instances where judges had recused themselves from cases where one of the parties was considering them for employment -- or seen their decisions later vacated because of that fact, even with no suggestion of a quid pro quo with the judge.

While potential candidates for judicial posts can't be expected to recuse themselves from routine cases involving the government, the Hamdan case differs because of the personal involvement of the president, who not only created the disputed commissions by executive order, but also selected Mr. Hamdan as eligible for prosecution, wrote Professors Stephen Gillers of New York University, David Luban of Georgetown University and Steven Lubet of Northwestern University.

After the article was published, two Democrats on the Senate Judiciary Committee, Russell Feingold of Wisconsin and Charles Schumer of New York, wrote Judge Roberts this week asking him to explain why he didn't recuse himself and whether he researched the propriety of remaining on the case.

Democrats studying Judge Roberts's legal opinions and prior work in the Reagan and first Bush administrations have found little to like about his conservative policy views. But until now, no ethical questions have been raised.

The White House responded by marshaling two legal experts, including one who recently completed a term as a Defense Department adviser on the military commissions, George Mason University Prof. Ronald Rotunda. In letters addressed to Judiciary Committee Chairman Arlen Specter, Prof. Rotunda and Professor Thomas D. Morgan of George Washington University argued that Judge Roberts's impartiality could not "reasonably be questioned," so he broke no legal or ethical rules.

Sen. Specter, the Pennsylvania Republican who will oversee the Roberts confirmation hearings that begin Sept. 6, says both sides have a point.

"In a perfect world, Roberts might have said something, but here you faced a unanimous court," where he wasn't the deciding vote, Sen. Specter said. "To step out would have delayed a decision on a very important matter."

But in the end, what happens may not be up to Cmdr. Swift or anyone directly involved in either the Hamdan case or the Roberts confirmation. The ruling Judge Roberts joined spells trouble, by implication, for claims brought by dozens of other Guantanamo prisoners being held without trial. Attorneys for those prisoners, eager to dislodge an unhelpful precedent, could raise questions about the validity of a ruling Judge Roberts joined.

Commentary:
In an era in which everything has to be reduced to a sound bite, it's hard to destroy Roberts with these very serious charges. But, look at it this way. If you were being judged by Roberts and he didn't recuse himself from a case in which he had business dealings with the prosecutor what would you think? Fair trial? Not a chance. He's unfit.