Even viewed in isolation, the decision has considerable weight.
But the ruling, which applies nationwide for the moment, comes as Washington whips itself into a security frenzy following the failed bombing Christmas day of an international U.S. flight from the Netherlands to Detroit, prompting warnings from civil rights and Muslim advocates.
The 2-1 ruling was handed down in the case of a Guantanamo detainee seeking release through a constitutional, or habeas, review of his case. But instead of being a paean to the power of the writ of habeas corpus, language in the opinions supporting the ruling may instead serve as a rallying cry for those who say it is time for the president and Congress to face reality and recognize the old rules no longer apply.
U.S. Circuit Judge Janice Rogers Brown wrote the majority opinion, and a separate concurrent opinion agreeing with the majority document. In that second opinion, in a highly unusual departure from judicial custom, Brown sets out a chilling vision of the stakes and new tactics in the war against terror.
"War is a challenge to law, and the law must adjust," Brown wrote. "It must recognize that the old wine skins of international law, domestic criminal procedure or other prior frameworks are ill-suited to the bitter wine of this new warfare. We can no longer afford diffidence. This war has placed us not just at, but already past the leading edge of a new and frightening paradigm, one that demands new rules be written. Falling back on the comfort of prior practices supplies only illusory comfort."
The U.S. Court of Appeals for the District of Columbia Circuit is sometimes called the second highest court in the land. It reviews all cases arising from Guantanamo claims, and its decisions in that venue must be followed by the other U.S. circuit courts of appeal.
The case before it was brought by Ghaleb Nassar al-Bihani, a Yemeni citizen, who has been held at the U.S. detention facility in Guantanamo Bay, Cuba, since 2002.
In early 2001, at the urging of a local sheik, al-Bihani traveled through Pakistan to Afghanistan, hoping to defend the Taliban's Islamic government against the Northern Alliance. The government says along the way he stayed at al-Qaida guest houses though al-Bihani insists they were affiliated only with the Taliban.
Joining the paramilitary 55th Arab Brigade as a cook, he retreated with that group until surrendering to the Northern Alliance, which turned him over to U.S.-led coalition forces that had invaded Afghanistan after the Sept. 11, 2001, terror attacks in the United States.
The 55th had al-Qaida fighters within its command structure.
Al-Bihani was sent to Guantanamo, but after the Supreme Court ruled in 2004's Rasul vs. Bush that federal courts had the jurisdiction to conduct constitutional reviews of detainee cases, lawyers representing him filed a petition for habeas review in Washington.
While al-Bihani's petition was stayed in limbo, the Supreme Court ruled in 2008's Boumediene vs. Bush that Congress, in the Military Commissions Act, unconstitutionally suspended the writ of habeas corpus for Guantanamo detainees.
Despite Boumediene, a district judge eventually denied al-Bihani's petition for review and release.
In his appeal, al-Bihani challenged "the statutory legitimacy of his detention by advancing a number of arguments based on the international laws of war," the appeals court majority opinion said. Al-Bihani argued "'support,' or even 'substantial support' of al-Qaida or the Taliban as an independent basis for detention violates international law. ... Al-Bihani interprets international law to mean anyone not belonging to an official state military is a civilian, and civilians, he says, must commit a direct hostile act, such as firing a weapon in combat, before they can be lawfully detained."
He also argued that members of the 55th Arab Brigade "did not have the required opportunity to declare its neutrality in the fight against the United States," and "an international war between the United States and Taliban-controlled Afghanistan officially ended when the Taliban lost control of the Afghan government. Thus, absent a determination of future dangerousness, he must be released. See Geneva Convention Relative to the Treatment of Prisoners of War," the majority opinion said.
The opinion said all of al-Bihani's arguments "rely heavily on the premise that the war powers granted by the (congressional Authorization for Use of Military Force) and other statutes are limited by the international laws of war. This premise is mistaken. There is no indication in the AUMF, the Detainee Treatment Act of 2005 ... or the MCA of 2006 or 2009, that Congress intended the international laws of war to act as extra-textual limiting principles for the president's war powers under the AUMF. The international laws of war as a whole have not been implemented domestically by Congress and are therefore not a source of authority for U.S. courts. ...
"Therefore, putting aside that we find al-Bihani's reading of international law to be unpersuasive, we have no occasion here to quibble over the intricate application of vague treaty provisions and amorphous customary principles," the opinion added. "The sources we look to for resolution of al-Bihani's case are the sources courts always look to: The text of relevant statutes and controlling domestic case law. Under those sources, al-Bihani is lawfully detained."
All three judges on the appellate panel agreed al-Bihani's release should be denied, but one dissenter said international law does apply to the case. The ruling will apply to all Guantanamo detention cases, unless overruled by the full circuit court or the Supreme Court.
The decision brought a response from Jonathan Hafetz, staff attorney with the American Civil Liberties Union's National Security Project.
"After eight years, the continued detention of prisoners without charge is an affront to the Constitution," Hafetz said in a statement. "Today's court opinion is a setback to justice and the rule of law. The unnecessary endorsement of excessive military detention power and the suggestion that America is free to defy international law flouts all precedent and, if actually adopted, would jeopardize America's security as well as its values."
Meanwhile, the Obama administration has suspended the release of Guantanamo detainees to Yemen, where al-Qaida in the Arabian Peninsula threatens the government and is said to be targeting U.S. assets and personnel. Published reports say earlier Guantanamo detainees released to Yemen during the Bush administration joined al-Qaida once they entered that country.
With President Barack Obama calling for a security crackdown, and civil libertarians protesting what they call racial profiling and full-body scans at airports, the Washington stage is set for a political and legal battle in which a federal appellate judge says even the law "must adjust" to the war on terror.