The Defense Department has released a list of ten now former Guantanamo detainees who were transferred to Oman earlier this week. One of them is Mohammed Al Ansi, a Yemeni who was captured in northern Pakistan in late 2001 and transferred to the detention facility in Cuba in Jan. 2002.

US authorities repeatedly found that Ansi (seen on the right) may have been selected to take part in an aborted part of the 9/11 hijackings.

Joint Task Force Guantanamo (JTF-GTMO) concluded in a leaked threat assessment, dated May 17, 2008, that Ansi “swore bayat (oath of allegiance) to” Osama bin Laden “and received specialized close combat training for his role as a suicide operative in an aborted component of the 11 September 2001 al Qaeda attacks.”

Another version of the allegation was included in a summary prepared by the Obama administration for the Periodic Review Board (PRB) process at Guantanamo.

“Judging from other detainee statements and corroborating information,” the Oct. 14, 2015 summary reads, Ansi “participated in advanced combat training and may have met with al Qaeda external operations chief Khalid Shaykh Mohammed … in Karachi and been considered for participation in a suicide attack or deployment in the West.”

Al Qaeda originally considered hijacking US airliners leaving from airports in Southeast Asia as part of the 9/11 plot. But bin Laden reportedly canceled this part of the operation because he thought it would be difficult to coordinate the additional hijackings.

According to the US government’s files, one of the ringleaders for the canceled 9/11 hijackings was Walid Bin Attash, a senior al Qaeda operative who helped plot the Oct. 2000 USS Cole bombing. Bin Attash allegedly performed surveillance on American airliners operating in Southeast Asia. After his part of the plot was called off, Bin Attash turned his attention to other al Qaeda plans.

Bin Attash, who is currently held at Guantanamo, fingered Ansi and three other detainees as would-be participants in the airliner plot. Leaked threat assessments prepared by JTF-GTMO, as well as files prepared for the detainees’ PRB hearings, link all four of them to the initial plan. Two of them were previously transferred by the Obama administration. Abdul Rahman Shalabi, a Saudi, was transferred to his home country on Sept. 22, 2015. Abd al Malik Abd al Wahab, a Yemeni, was transferred to Montenegro on June 22, 2016.

Only the fourth detainee identified by Bin Attash as being part of the plot, a Yemeni named Zuhail Abdo Anam Said al Sharabi, remains in US custody at Guantanamo. A summary prepared for Sharabi’s PRB hearing notes that he traveled to Malaysia, where he stayed with Bin Attash and two of the 9/11 hijackers. Sharabi apparently denied this allegation during questioning, but also described the pair of 9/11 hijackers as “martyrs.” JTF-GTMO’s analysts found that Sharabi’s trip to Malaysia with Bin Attash was ordered by Osama bin Laden himself as “part of the pre-planning for the hijacking plot.” The pair stayed at the home of Hambali, a notorious al Qaeda leader in Southeast Asia who is also still detained at Guantanamo.

Bin Attash told authorities that, just two months prior to 9/11, Khalid Sheikh Mohammed (KSM) took the four (including Ansi), as well as two others, “to Karachi to teach them English language and American culture.”

Bodyguards for Osama bin Laden

Ansi, Shalabi, and Wahab were all captured on Dec. 15, 2001, as they crossed the Afghan border into Pakistan. All three were assessed to be bodyguards for Osama bin Laden. They were captured after allegedly fleeing the Battle of Tora Bora. The group they belonged to was dubbed the “Dirty 30” by US intelligence. Its most infamous member is Mohammed al Qahtani, who was slated to take part in the 9/11 hijackings, but was denied entry into the US in the summer of 2001.

JTF-GTMO found that Sharabi was also a bodyguard for bin Laden, but he was detained separately during a raid in Karachi in Feb. 2002. A senior al Qaeda facilitator and more than one dozen other al Qaeda fighters were captured alongside him.

Deemed “high” risks and denied transfer for years

JTF-GTMO deemed all four of the conspirators, including Ansi, “high” risks to the US, its interests and allies. As of 2008, JTF-GTMO also recommended that they remain in continued detention.

President Obama’s Guantanamo Review Task Force, which finished its work in Jan. 2010, agreed with JTF-GTMO’s recommendations. The task force concluded that Ansi, Shalabi, and Wahab should remain in US custody under the 2001 Authorization for Use of Military Force (AUMF), because they were too dangerous to transfer but prosecution was considered infeasible. Sharabi was referred for prosecution, but he still hasn’t been tried seven years later.

Ansi, Shalabi, and Wahab were eventually approved for transfer during the PRB process, which was established by President Obama in 2011. But the decision to transfer them does not mean that they were suddenly deemed innocent, or that the PRB considered them to be risk-free.

In fact, the PRB even ruled against Ansi less than one year ago.

In its Mar. 23, 2016 decision, the PRB determined that “continued law of war detention of the detainee [Ansi] remains necessary to protect against a continuing significant threat to the security of the United States.”

“In making this determination,” the decision continued, “the Board considered the significant derogatory information regarding the detainee’s past activities in Afghanistan.” The PRB “noted” Ansi’s “lack of candor resulting in an inability to assess the detainee’s credibility and therefore his further intentions.”

The PRB left the door open for Ansi to win approval for transfer just several months later. “The Board looks forward to reviewing the detainee’s file in six months and encourages the detainee to continue to be compliant, continue taking advantage of educational opportunities and continue working with the doctors to maintain his health,” the PRB wrote. “The Board encourages the detainee to be increasingly forthcoming in communications with the Board.”

Less than nine months later, on Dec. 9. 2016, the PRB reversed its previous decision, finding that Ansi’s detention “is no longer necessary to protect against a continuing significant threat to the security of the United States.” In March, Ansi lacked candor. But by December Ansi had suddenly “demonstrated candor and provided details of his pre-detention activities and mindset.” He also supposedly did “not appear to be driven to reengage by extremist ideology,” the PRB wrote.

The PRB still did not say that Ansi could be outright released. Instead, the board stated that the “threat” Ansi “presents can be adequately mitigated,” as long as he was transferred to a country with a “strong rehabilitation and reintegration program” and “appropriate security assurances” were put in place. The PRB previously issued similar rulings for both Shalabi and Wahab.

Just over one month after the PRB’s revised decision, Ansi was transferred along with nine others to Oman.

Of the four detainees identified by Bin Attash as participants in the aborted 9/11 plot, only Sharabi has been denied transfer by the PRB. The review board cited Sharabi’s “possible participation in KSM’s plot to conduct 9/11-style attacks in Southeast Asia.”

Thomas Joscelyn is a Senior Fellow at the Foundation for Defense of Democracies and the Senior Editor for FDD's Long War Journal.

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