The US Supreme Court on Monday declined a plea from lawyers for a longtime Guantánamo detainee to examine whether federal judges are applying a rigorous enough legal standard when assessing whether the American military has enough evidence to continue to hold suspected enemy combatants indefinitely without charge at the Guantánamo prison camp.

At issue in the appeal was whether the lower courts are following the requirements of a 2008 Supreme Court decision called Boumediene v. Bush.

In that case the high court announced that Guantánamo detainees were entitled to challenge the legality of their open-ended detentions and that the lower courts must provide a “meaningful review” of their cases.

The petition before the court involved a Yemen citizen named Abdul Al Qader Ahmed Hussain. He was arrested by Pakistan authorities in Faisalabad, Pakistan, in March 2002, and turned over to US officials for questioning.

He was sent to Guantánamo. Today, Mr. Hussain is 29 years old. He has spent more than a third of his life at Guantánamo.

The Supreme Court gave no explanation of its denial of the Hussain petition. But Justice Stephen Breyer suggested in a two-page statement that the petition did not raise the most relevant question.

He noted that Congress authorized the military to detain enemy combatants. The courts have defined an enemy combatant as an individual who was part of or was supporting forces hostile to the United States or coalition partners in Afghanistan. It applies particularly to members and supporters of Al Qaeda and the Taliban. The individuals must also have engaged in armed conflict against the United States in Afghanistan, according to the definition.

Justice Breyer said that a federal judge and a federal appeals court had upheld the open-ended detention of Hussain because he was “part of Al-Qaeda or the Taliban at the time of his apprehension.”

But Breyer said that even if such an association were correct, it may not be enough to satisfy the full showing necessary to prove enemy combatant status.

“It is possible that Hussain was not an ‘individual who … was part of or supporting forces hostile to the United States or coalition partners in Afghanistan and who engaged in an armed conflict against the United States there,’ " Breyer said.

He noted: “The Court has not directly addressed whether [federal law authorizes], and the Constitution permits, detention on the basis that an individual was part of Al-Qaeda, or part of the Taliban, but was not ‘engaged in an armed conflict against the United States’ in Afghanistan prior to his capture.”

Breyer added that the high court had also not considered whether federal law or the US Constitution would limit the duration of detention.

“The circumstances of Hussain’s detention may involve these unanswered questions, but his petition does not ask us to answer them,” Breyer said.

On that basis, Breyer said he agreed with the court’s decision to decline to hear Hussain’s case.

In their petition to the court, Hussain’s lawyers had said there was insufficient evidence that Hussain was a part of Al Qaeda, the Taliban, or any associated enemy forces opposed to the United States.

They said the only reason he is still being held is because the lower courts are applying an exceedingly skimpy burden of proof that allows the US government to hold almost anyone indefinitely without charge and with no prospect of a full trial.

“In this case and other Guantánamo habeas cases, the Court of Appeals has applied its ‘functional’ test in a manner that permits detention under virtually any set of facts,” Wesley Powell of the New York law firm Willkie Farr & Gallagher wrote in his brief urging the high court to take up Hussain’s case.

“This watered-down review directly contravenes the directive of this Court in Boumediene that habeas courts reviewing the legality of Guantánamo detainees’ detention ‘conduct a meaningful review,’ " Mr. Powell said.

Government lawyers argued that they have met the necessary burden of proof demonstrating that Hussain was part of enemy forces at the time of his capture.

“Most clearly, [Hussain] admitted to carrying an AK-47 assault rifle during an extended stay with Taliban forces near the front lines of a battlefield in Afghanistan,” US Solicitor General Donald Verrilli wrote in his brief urging the court to dismiss the appeal.

He said further review by the courts was unwarranted.

Powell said the government must be required to prove the existence of a relationship between Hussain and an enemy organization.

“The government does not contest what it cannot deny – Mr. Hussain never used the gun, engaged in battle, or otherwise supported the activities of Al-Qaeda or the Taliban,” Powell said.

Here is the essence of the government’s case against Hussain.

In 1999, he traveled from Yemen to Pakistan and stayed for three months at a mosque in Quetta run by Jama’at al-Tablighi, a group that the US government has designated as a provider of operational and financial support to Al Qaeda.

From the mosque, he traveled to Kabul, Afghanistan. According to the US government, by traveling from Karachi to Kabul via Quetta and Kandahar, Hussain had followed a “common Al Qaeda route.”

Hussain stayed in Kabul for three months and then returned to the Jama’at al-Tablighi mosque in Quetta.

The government says he returned to Kabul for a few more months and then went back to the mosque in Quetta.

Hussain made a third trip to Kabul in November 2000. On that trip, Hussain has said he met three Taliban fighters in a market. They invited him to travel with them to an area north of Kabul where Taliban forces were facing opposing forces of the Northern Alliance.

Hussain “admitted that a Taliban fighter provided him with an AK-47 assault rifle and taught him how to use it.” Hussain told the court that he lived with the fighters near the front lines for 10 months.

He returned to Kabul in August 2001. In the fall of 2001, with Northern Alliance forces advancing and capturing Kabul, Hussain traveled to Pakistan, crossing the border unlawfully, and stayed at a Jama’at al-Tiblighi mosque in Lahore. He then traveled to Faisalabad and lived in a group house. After spending six months in Pakistan, he was arrested by Pakistani authorities who turned him over to the US military.

“From these facts, the district court concluded that it was more likely than not that [Hussain] was part of al Qaeda or Taliban forces at the time of his capture and thus is detainable,” the government brief says.

Powell says in his brief that thousands of Muslim travelers who have nothing to do with Al Qaeda stay at Jama’at al-Tablighi mosques. Hussain's presence at the mosques is insufficient to support a finding that he was “more likely than not part of enemy forces.”

In its review, the court of appeals placed special emphasis on Hussain’s 10 months near the battlefield north of Kabul when he was given a rifle. The court applied what it called a “walks like a duck” test to surmise that anyone in that area given a rifle would be loyal to those enemy forces.

One member of the appeals court panel, however, said such an analysis is not a proper application of the burden of proof. He added: “And it is quite invidious because, arguably, any young Muslim man traveling or temporarily residing in areas in which terrorists are known to operate would pass the ‘duck test.’ That is exactly why the Court should faithfully apply the proper evidentiary standard.”

Powell said the appeals court placed great weight on this aspect of the case. But he noted that the federal judge who conducted a three-day hearing “made no findings that Hussain used the gun, engaged in battle, or otherwise supported the activities of al Qaeda or the Taliban.”

“It is high time this Court hold the government and the lower courts to the meaningful review of detention promised in Boumediene, and this case presents the Court with the perfect opportunity to do so,” Powell said in his petition.

The case was Hussain v. Obama (13-638).