In two little noted decisions, the Obama administration has decided to go ahead with the Guantánamo prosecution of an Afghan detainee who allegedly hid mines in his homeland and late last year quietly sent home another captive who was once taken to the war court for allegedly spying on U.S. soldiers in Afghanistan.

On Dec. 20, U.S. troops released Mohammed Hashim among a dozen detainees let go from the U.S. Navy base in the last transfer of captives that sent six to Yemen, four to Afghanistan and two to Somaliland. Until his release, Hashim was charged with war crimes, first sworn out in 2008, that alleged he had carried out surveillance on U.S. forces in Afghanistan in the first year of the invasion, specifically at a Forward Operating Base called Gecko.

A Justice Department statement said in response to a Miami Herald inquiry that a U.S. task force unanimously agreed to let him go -- ``consistent with the national security interests of the United States'' -- as part of the ongoing churn of cases as the Obama administration reviews the detainee population at Guantánamo.

The December 2009 release, specifically of six long-held captives back to Yemen, has stirred controversy in U.S. domestic politics since a Nigerian man's Christmas Day attempt to blow up a Detroit-bound airliner -- allegedly with help from a Yemeni-based al Qaeda offshoot led by two freed Saudi Guantánamo detainees.

The Dec. 20 transfer, a major operation at the close of the year, reduced the prison camps census to 198 foreign men from 28 nations amid an Obama administration push to close the detention center.

Agencies that signed off on the release of all 12 detainees included representatives of the Office of the Director of National Intelligence and, the Departments of Defense, State, Justice and Homeland Security, the statement said.

``That review examined a number of factors, including potential threat, mitigation measures and the likelihood of success in habeas litigation,'' it added.

Hashim, born in Kandahar in 1976, was taken before a Marine Corps judge at Guantánamo's Camp Justice Nov. 20, 2008, two days after President Barack Obama's election in a little-noticed hearing attended by a lone reporter.

Pentagon documents alleged that the Afghan had boasted to military interrogators that he helped Osama bin Laden elude capture by the Americans in the 2001 U.S. invasion of his homeland. But he was instead charged with spying and providing material support for terror.

Once he was released, Pentagon prosecutors withdrew the charges, but issued no explanation.

In contrast, the Justice Department disclosed for the first time in a brief filed Wednesday at a federal appeals court that Attorney General Eric Holder had approved a military commissions prosecution in the case of an Afghan detainee named Obaidullah.

Obaidullah, born in Khost in 1980, has never gone before a war court. Military prosecutors first swore out charges against him in 2008, alleging he hid mines and other explosives in the Khost area of Afghanistan from October 2001 to July 2002. He also allegedly had a notebook with instructions on how to use them.

The Hashim case marked the first about-face in a military commissions prosecution that was not mandated by a federal judge.

``He was in good health. He was returned to Afghanistan in accordance with his wishes,'' said his civilian attorney Steven Kilpack, a federal public defender in Utah, who could not shed light on the decision to free him.