That’s been left to the federal district courts hearing the habeas corpus cases of Guantanamo detainees’ to decide, and yesterday, Judge John Bates, a Bush appointee on the federal court in Washington, D.C., significantly narrowed the definition of who can legitimately be deemed a combatant (pdf). He did not, however, reject the government’s claim that under the laws of war, it can hold enemy fighters indefinitely — much to the dismay of some of the detainees’ defense lawyers.

The Obama administration had claimed “the authority to detain persons that the President determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001″; “persons who harbored those responsible for those attacks; “and “persons who were part of, or substantially supported, Taliban or al Qaida forces or associated forces that are engaged in hostilities against the United States or its coalition partners, including any person who has committed a belligerent act, or has directly supported hostilities, in aid of such enemy armed forces.”

Bates, while accepting the still-controversial view that the laws of war allow the president to detain al-Qaeda or Taliban fighters indefinitely, refused to extend that to those who “support” those groups, saying “the Court can find no authority in domestic law or the law of war, nor can the government point to any, to justify the concept of “support” as a valid ground for detention.”

However, citing Congress’s declaration in the Authorization for the Use of Military Force (AUMF) against organizations that the president determines attacked the United States on September 11, 2001 and analogizing from the laws of war, Bates concluded that the government can detain members of al-Qaeda and the Taliban, and members of “associated forces” or “co-belligerents.”

But how do you prove who was a “member” of al-Qaeda or the Taliban? Members of terrorist organizations don’t wear uniforms or carry cards declaring their membership. And that’s, of course, what the government and defense lawyers will be fighting out over the coming months.

Already, in several cases — such as in the Alla Ali Bin Ali Ahmed case that I wrote about here — judges have determined that the government did not have enough evidence to support its “membership” claim. Staying in a guest house frequented by al-Qaeda members, for example, was not enough to prove membership. And tending to al-Qaeda members as a doctor or cleric, Bates pointed out in his opinion yesterday, would not alone be enough.

Defense lawyers representing Gitmo detainees say that in many of their cases, that’s exactly the sort of flimsy evidence the government is claiming justifies the detainees’ indefinite detention until the end of the “war on terror.” Bates yesterday brought those detainees a step closer to their eventual release.

U.S. District Court Judge John Bates ruled that the four men — all foreign nationals captured by U.S. forces outside Afghanistan and sent there to be incarcerated at a prison on the U.S.-run Bagram air base — have the same rights as prisoners at Guantanamo Bay, who were similarly sent there by U.S. forces from other countries.

As I’ve written before, the Bagram prison — which is fast turning into Obama’s Gitmo — has many of the same attributes as the U.S. prison at Guantanamo Bay. That’s just what the lawyers for the four detainees there argued.  Although the Obama administration had, like the Bush administration before it, argued forcefully that Bagram detainees have no constitutional rights and therefore no rights to challenge their detention in U.S. courts, Bates — a conservative judge appointed by former President George W. Bush — today disagreed.

“The writ of habeas corpus plays a central role in our constitutional system as conceived by the Framers,” wrote Judge Bates. “Indeed, ‘the Framers deemed the writ to be an essential mechanism in the separation-of-powers scheme,’ ” he wrote, quoting the Supreme Court’s recent decision in Boumediene v. Bush, which gave Guantanamo detainees habeas corpus rights, “that, as Alexander Hamilton observed, was vital to the protection of individuals against the very same arbitrary exercise of the government’s power to detain that is alleged by petitioners here.”

Although all four of the detainees in the case were captured outside Afghanistan and have been held at Bagram for more than six years, Bates ruled that one of the men, who is an Afghan citizen, may not be entitled to habeas corpus review because of the “practical obstacles in the form of friction with the host country.” He ordered the lawyers to file additional briefs with the court addressing those issues.

As we reported back in the first week of January, the Bagram prison holds almost three times as many prisoners as the Guantanamo Bay detention facility does, but President Obama, despite pledging to close Gitmo and provide all detainees there humane conditions and due process, hasn’t said a word yet about what he’ll do about Bagram.

To be sure, it’s a somewhat thornier problem, as I described in my earlier piece, in that the Defense Department claims a lot of the Bagram prisoners were picked up “on the battlefield” in Afghanistan, and that the United States is therefore entitled to hold them. But as a legal matter, that’s not at all clear: after all, we’re not at war with the government of Afghanistan, and just calling these guys “enemy combatants” doesn’t necessarily answer the question.

What’s more, the administrative review that is supposed to determine the detainees’ status often consists of just one commanding officer deciding based on information provided by their captors. See Col. Rose Miller’s declaration, describing the process and submitted in connection with one of the Bagram cases, here (pdf). The detainees themselves, who have no access to lawyers or even the evidence against them, have no right to attend any hearings on the matter or subsequent reviews.

Finally, one thing glossed over in today’s piece in The Times is that while the Defense Department says it’s been turning 20-30 prisoners a month over to the Afghans for trials, these are hardly what we in the United States would consider a “trial.” Volunteer lawyers from a nonprofiit organization called the International Legal Foundation, which has tried to represent the Afghans in those proceedings, have told me that they often learn of the charges against their client just a day or even hours in advance, and have no time to prepare their case, let alone access to the evidence against the prisoner.

I described one such trial in a magazine article I wrote for The American Lawyer last fall about the case of an Afghan man named Ruzatullah, who described the proceeding to Tina Foster, an American lawyer representing him in a habeas corpus proceeding:

A panel of Afghan judges read a statement charging that Ruzatullah had aided terrorists. The only “evidence” presented, said Foster, was that his captors had found names of “government enemies” in Ruzatullah’s diary; his mobile phone number was in the possession of other suspects who had been killed by coalition and Afghan forces; Ruzatullah had graduated from a university that many antigovernment suspects have attended; and he had been living in a refugee camp believed to serve as a base for government enemies. The judges, who acted also as prosecutors, did not present any witnesses or sworn statements to support the charges, he told Foster. During the proceeding, Shabeer [his Afghan lawyer] objected that there was no evidence to support the claims; the names in the diary had not been written by Ruzatullah; and many who had attended the same university or lived in the refugee camp were neither terrorists nor enemies of the Afghan or U.S. government. Ruzatullah himself also denied the charges at the trial. Two days after the trial, he told Foster, Ruzatullah was informed that he had been convicted and sentenced to three-and-a-half years in prison. Because he had already spent almost that much time in detention, however, he had only a month left in his sentence. Ruzatullah was released last spring.

“They convicted him on the say-so of the U.S. government without any supporting evidence,” said Foster. Foster is the executive director of the International Justice Network, which has taken the lead in representing Bagram detainees in the United States. She represented Ruzatullah in a habeas corpus proceeding that was dismissed as moot as soon as Ruzatullah was transferred to Afghan custody.

Foster and other lawyers have charged that one reason their clients were transferred by the Defense Department under the Bush administration was to avoid rulings on their habeas cases that were pending in a U.S. federal court.

The Obama administration has so far not used that tactic; as we reported earlier, the cases of four Bagram prisoners are now pending in U.S. District Court in Washington, D.C. The judge in that case has ordered the Defense Department to produce more information about the detainees at Bagram, and specifically ordered the Obama administration last week to clarify the position it intends to take on this group of detainees, in light of its recent executive orders, by Feb. 20.