The United States sent home to Sudan on Tuesday one of Guantánamo’s longest-held prisoners, a 52-year-old confessed al Qaida foot soldier and sometime driver for Osama bin Laden whose release was seen as a crucial test case of the Barack Obama-era war court.

Ibrahim al Qosi pleaded guilty to terror charges in July 2010 in exchange for the possibility of release after serving a two-year sentence.

U.S. troops spirited him from the remote base days after his war crimes sentence ran out and dropped him off in the capital city Khartoum about 8 p.m. Miami time Tuesday night, Wednesday in Sudan, U.S. government sources said.

The Pentagon has not yet disclosed the transfer — which reduced the number of foreign prisoners at the Navy base in Cuba to 168 — to give Sudanese officials time to put the returnee in a rehabilitation program in the Horn of Africa nation. But the repatriation demonstrated that the Obama administration is still in the business of deal-making and downsizing the prison camps even as the Defense Department is planning to spend $40 million on an undersea telecommunications cable to the base in southeast Cuba.

Now-grown “child soldier” Omar Khadr could go next, to a lock-up in his native Canada. The White House is also reportedly considering transferring some Taliban captives at Guantánamo to Afghanistan as part of a regional peace accord there.

The release of Qosi was the first of a convicted war criminal since the Bush administration sent home Yemeni Salim Hamdan in 2008. Qosi’s attorney argued the U.S. had no reason to fear the Sudanese man.

“He is now in his 50s, eager only to spend his life at home with his family in Sudan — his mother and father, his wife and two teenage daughters, and his brothers and their families — and live among them in peace, quiet and freedom,” said Washington, D.C., attorney Paul Reichler, who defended Qosi without charge for seven years.

Although Qosi finished his prison sentence, repatriation wasn’t certain. Under Obama doctrine, like George W. Bush’s before, the U.S. argues it can lawfully hold a convict indefinitely after his sentence is over by moving him out of the maximum-security Convict’s Block to the communal POW-style lockup where most Guantánamo captives are held.

Instead, camp guards moved Qosi last week to special quarters that had a flat-screen TV, a refrigerator that let him eat at his leisure and a small outdoor gravel-topped patio, all inside a locked enclosure, said his Pentagon defense lawyer, Navy Cmdr. Suzanne Lachelier. It also had a real bed rather than a steel bunk topped with a mat. Qosi spurned the bed, the lawyer said, because he suffers from a bad back and slept on the floor in the days before his departure.

Word of the repatriation in the camps may break a logjam in plea deals attributed to the Khadr case.

The Canadian, now 25, could have gone home in October to serve more of an eight-year sentence he got for pleading guilty to hurling a grenade that killed a U.S. soldier in a firefight in Afghanistan in 2002. But Canada has yet to formally ask for his return, and the lack of any release, defense lawyers say, has meant that prosecution plea deal offers have fallen on deaf ears.

“Clearly if the government can’t carry through on their end of the bargain, it has a chilling effect on the willingness of others to plead,” said Marine Col. Jeffrey Colwell, chief defense counsel for military commissions. “Certainly there was an expectation by all parties involved that Khadr was going to be home last fall,” he said. “It’s July, and he’s not.’’