The Obama administration has released one of al Qaeda’s most skilled explosives experts, a man personally praised by Osama bin Laden and who created the shoe-bomb design that was used unsuccessfully to bring down an airliner in 2001.

It is hard to act surprised at decisions like this in light of the recent downsizing of the Guantanamo population. Al Sawah is one of several new detainees to be released by the Obama administration. He was such a compliant and valuable intelligence asset during his 14 years of captivity that he is afraid to leave the facility, and has in fact refused to leave. He fears for his life if he returns to freedom due to the threat of terror groups who are well aware of his compliance with US authorities.

One particularly interesting aspect of the whole situation is with a detainee refusing to leave, what will the Obama administration do if they move forward with the planned closure of Guantanamo? Will they transfer him to the states at the ire of the majority of US citizens? One thing is for sure, a high-value al Qaeda bomb maker has been freed with no clear reason why.

The Pentagon said Thursday that Egyptian Tariq Mahmoud Ahmed al Sawah, who may have known of the original Sept. 11 plot, was transferred to the government of Bosnia. Al Sawah fought with the Bosnian army in the early 1990s and eventually made his way to Afghanistan in 2000.

Like other members of al Qaeda, al Sawah began his terrorism career as a member of the secretive Muslim Brotherhood, which is present in the U.S.

Al Sawah’s Guantanamo file reveals a number of chronic medical problems in 2008, when a secret profile was created by Task Force Guantanamo. Now 58, he was listed as “morbidly obese,” and at the time suffered from diabetes, fatty liver disease and chronic pain from spinal cord compression. Prison doctors urged him to get more exercise.

In his terrorism career, he was close to bin Laden and taught classes in explosives at the al Qaeda leader’s Tarnak Farms training camp.

Largest transfer of Gitmo detainees under Obama announced

Read Next: Largest transfer of Gitmo detainees under Obama announced

In Afghanistan al Sawah developed a mine to sink U.S. ships and the shoe-bomb prototype that Richard Reid attempted to ignite while on a flight from Paris to Miami in December 2001.

“Detainee also associated with the planners and perpetrators of international terrorist attacks and other senior al-Qaida members, and may have had advanced knowledge of the 11 September 2001 attacks,” states his secret file, which was published by Wikileaks along with hundreds of other Gitmo dossiers. “Detainee participated in hostilities against U.S. and Coalition forces, and is a veteran extremist combatant.”

Joint Task Force Guantanamo judged al Sawah to be a “medium” risk to U.S. troops and recommended him for transfer.

The publicized file may prove a problem for al Sawah on the outside. He became an “exceptional” intelligence source, his file says, which could cause terrorists to seek revenge.

“He has been compliant over the last four years,” the file says. “He continues to be a highly prolific source and has provided invaluable intelligence regarding explosives, al-Qaida, affiliated entities and their activities. If released, detainee will possibly reestablish extremist associations, but is unlikely to do so as his cooperation with the U.S. government may serve to identify detainee as a target for revenge by those associates.”

His release brings the prison population, once at more than 700, to 92, including Sept. 11 mastermind Khalid Sheikh Mohammed.

President Obama plans to close the prison and bring whoever is left at Gitmo to an American prison.