Last week the Obama administration announced that it is shuttering the office tasked with closing Guantanamo Bay prison. The storied facility will soldier on, despite its questionable treatment of prisoners and their lawyers, its opaqueness and secrecy—and above all, prosecutors’ flimsy record on convicting actual terrorists.

Of the hundreds of prisoners who have cycled through the Guantanamo Bay military prison, only a handful have been convicted of anything. Now, thanks to a recent federal appellate court decision, even those convictions could be overturned, leading one to ask: what has the military tribunal been doing all these years?

Central to this question is a January 25 ruling that effectively reversed the conviction of Ali Hamza Bahlul, an al-Qaeda propagandist and once personal secretary to Osama bin Laden. He was convicted after a very brief trial in 2008 on charges of material support and conspiracy to commit terrorism. These “inchoate” or indirect offenses were invalid, according to the U.S. Court of Appeals for the District of Columbia Circuit, because they were not recognized as stand-alone war crimes when he was first captured in 2004, before the current military commission was convened in 2006.

This was the second such ruling in a year. In October, the same court (not considered a liberal by any definition), overturned the conviction of Salim Hamdan, who as bin Laden’s driver was picked up carrying weapons and al-Qaeda documents in Afghanistan in 2002 and was similarly charged with material support for terrorism. At the time of the verdict, the government was confident that the court’s decision—which ruled Hamdan could not be convicted on a charge that was not valid before 2006—was so narrow that it would have no affect on future cases.

But here we are, four months later, and one more prosecution bites the dust.

The government will not pursue an appeal for Hamdan, and it has not yet announced what it will do in al-Bahlul’s case. A recent Associated Press story suggested that the government is inclined to appeal, arguing that the U.S. Military Code of Justice gives it the authority to charge suspects with inchoate crimes under the American law of war (see their filings on al-Bahlul here).

“I think how important this is depends on what the government does next. If the government packs up and goes home and doesn’t pursue a further appeal it will be the last word, at least for now, on the government’s ability to try these inchoate offenses in military commissions,” said Steven Vladeck, professor at American University Washington College of Law.

If that happens, or an al-Bahlul appeal is brought to the Supreme Court and the government loses, Vladeck added, it “will drastically reduce the number of cases we will see after the KSM [Khalid Sheikh Mohammed] trial,” primarily because the vast majority of prisoners now at Gitmo were captured before 2006 and are not suspected of committing direct acts of terror.

Vladeck elaborates on why he thinks the government’s case for upholding conspiracy and material support as stand-alone charges is “thin” anyway, here.

“KSM” and his four 9/11 conspirators are the biggest fish to go before the commissions since Guantanamo opened shortly after the 2001 terror attacks. Zacarias Moussaoui, tried as the “20th hijacker” on felony conspiracy charges for his role in 9/11, was convicted in federal civilian court in 2006. Critics point to the relatively short time it took to execute his case compared to the sluggish proceedings at Gitmo. (KSM was picked up in Pakistan in 2003, and his lawyers predict the trial, still in the pre-trial stage, could take years.)

Now Moussaoui is tucked away for life at a Supermax prison in Colorado, costing the tax payer an estimated $65,000 to $90,000 a year, while Gitmo has 166 prisoners—86 of whom have already been cleared for release—costing the taxpayer $800,000 each annually, according to Carol Rosenberg, longtime Guantanamo reporter for McClatchy News, who in 2011 called it the “most expensive prison on earth.” (Another assessment puts the per prisoner cost at $687,747.) Rosenberg notes that Gitmo is

still funded as an open-ended battlefield necessity, although the last prisoner arrived in March 2008. But it functions more like a gated community in an American suburb than a forward-operating base in one of Afghanistan’s violent provinces.

“From a fiscal point of view, this is just stupid. And the legal process has also failed to deliver as advertised,” Samuel Morison, a civilian lawyer with the Chief Defense Counsel for the U.S. Military Commissions, told The American Conservative in an interview. “If these guys had been sent to federal court we would have sorted this out a long time ago. The taxpayers are simply not getting their money’s worth.”

Aside from al-Bahlul and Hamdan, other convictions could be affected by the court’s recent ruling. These would include those of Australian David Hicks, who was convicted of material support and released in 2007; Ibrahim al-Qosi, who was released in July to his home country in Sudan after a conviction for material support and conspiracy; and Omar Khadr, who was picked up in 2002 at the age of 15 and was finally repatriated back to Canada in 2012 after pleading guilty to murder in violation of the laws of war, attempted murder in violation of the laws of war, conspiracy, material support, and spying. He is up for parole this year.

Experts who spoke with TAC said all three signed waivers in their plea agreements not to appeal their convictions. But Morison believes those waivers could be challenged as well.

“The ultimate result of this is that after 11 years and nearly 800 people who have been brought to Guantanamo … no more than a handful are likely to be charged with a crime,” he said. “They don’t have any evidence that most of these guys did anything other than maybe hanging around with the wrong crowd. That might be enough to charge you in federal court, but not in military court.”

Not much of a track record for a bureaucracy that has not only cost the American government $114 million a year but has put its reputation in a sling throughout the world. On Gitmo’s 11th anniversary last month, demonstrations were staged in cities across the globe, with much of the anger directed at President Obama—who had pledged to close the prison four years ago, and now looks to be digging in his heels.

Kelley Beaucar Vlahos is a Washington, D.C.-based freelance reporter and TAC contributing editor.

Follow @kelleybvlahos