When Attorney General Eric Holder announced in 2009 that Khalid Shaikh Mohammed and four other accused Sept. 11 conspirators would be tried in a civilian federal court, we said that his decision “makes an eloquent statement about the Obama administration’s determination to avenge the victims of terrorism within the rule of law.” But the five never made it to civilian court; instead, thanks to domestic politics, they are being tried on murder and other charges before a military commission in Guantanamo Bay.

The commission is not, as some of its detractors assert, a kangaroo court rigged to guarantee the conviction and execution of the defendants. But both substantively and symbolically, it is an unacceptable alternative to a civilian trial of the kind that has successfully convicted other terrorists.

The commission’s proceedings began inauspiciously when the defendants refused to enter pleas and staged a silent protest against the legitimacy of the tribunal. Defense lawyers have complained that they are being restricted in talking with clients about their treatment by CIA interrogators, and the American Civil Liberties Union is challenging a “protective order” proposed by the government that would treat the defendants’ statements about their interrogation as “presumptively classified” and thus subject to censorship.

NO GUARANTEES

There is no guarantee that the defendants wouldn’t behave in a similarly obstructive way in a civilian trial. Nor would the prosecutors in a federal court be prevented from asking the judge to withhold classified information. And civil libertarians who see the prosecution of the self-proclaimed Sept. 11 mastermind and his confederates as an opportunity to ventilate the CIA’s use of waterboarding and other abusive interrogation methods might find a civilian judge just as reluctant as a military one to put the CIA on trial.

That said, the differences between the two kinds of proceedings are important. The current military system, revised by Congress in 2009, is more credible than the commissions unilaterally established by the George W. Bush administration.

It requires proof of guilt beyond a reasonable doubt, prohibits double jeopardy and, most important, bars the admission of evidence obtained as the result of torture or “cruel, inhuman, or degrading treatment.” (Mohammed was repeatedly waterboarded.)

Yet in other respects it is less protective of defendants than a civilian trial. While evidence resulting from torture is inadmissible and confessions are required to be voluntary, critics say other sorts of “coerced” statements — particularly from third parties — could be allowed. The commission system is also more accepting of hearsay evidence.

As important as these particular defects is the fact that the trial of the Sept. 11 defendants is taking place under the aegis of the same military that is imprisoning them, and which has held them without successfully putting them on trial for almost a decade.

NOT GOLD STANDARD JUSTICE

Regardless of improvements in the commission system since the Bush administration, it simply doesn’t afford the defendants the gold standard of American justice. If Mohammed were sentenced to death after a civilian trial, the United States could point to the fact that it had provided full due process even to someone who murdered nearly 3,000 innocent people.

It can’t credibly make that claim about a military commission. And while, understandably, the families of Sept. 11 victims might not care about international opinion, the Obama administration recognized that it was in this country’s interest — especially after revelations about torture and the imprisonment of accused terrorists at “black sites” — for Mohammed and the others to receive a trial that was not only fair but perceived to be fair.

That is not going to happen. Much of the blame belongs to Congress, which effectively thwarted the administration’s original plan for a civilian trial by barring the transfer of Guantanamo detainees to the United States. But the administration also committed errors.

In announcing that the trial would be held in New York City, Holder provoked a backlash from residents and public officials who feared the city would again become a target for terrorists.

It would have been politically wiser if the administration had proposed a civilian trial at a more remote and protected site. Later, after the hardening of opposition to a civilian trial anywhere, the president decided not to expend political capital pressing for his original plan.

A civilian trial for Mohammed and the others would have dramatized Obama’s commitment at the beginning of his administration to depart decisively from Bush administration policies in the war against terrorism. The president should have fought harder for his original vision of justice.