A senior U.S. defense official confirmed Saturday that the prisoners to be released include Mullah Mohammad Fazl, Mullah Norullah Noori, Abdul Haq Wasiq, Khairullah Khairkhwa and Mohammed Nabi Omari.

While not as well known as Guantanamo inmates like 9-11 mastermind Khalid Sheikh Mohammed, the Taliban 5 were some of the worst outlaws in the U.S. war on terror. And their release will end up replenishing the diminished leadership ranks of the Afghan Taliban at a moment when the United States is winding down the war there.

“They are undoubtedly among the most dangerous Taliban commanders held at Guantanamo,” said Thomas Joscelyn, a senior editor at the Long War Journal who keeps a close watch on developments concerning the detainees left at the Guantanamo Bay prison.

Fazl, for example, was the Taliban’s former deputy defense minister and is wanted by the United Nations for his role in massacres targeting Afghan’s Shi’ite Muslim population.
According to the 2008 Pentagon’s dossier on Fazl disclosed by Wikileaks (PDF),  Noori also was a senior Taliban military figure and, according to his Pentagon dossier, was asked personally in 1995 by Osama bin Laden (PDF) to participate in an offensive against northern alliance warlord Rashid Dostum.

Wasiq, a former deputy minister of intelligence, at one point tried to cooperate with U.S. forces in Afghanistan and asked for a GPS system as well as a special radio to communicate with the U.S. military after the U.S. invasion in 2001. His dossier (PDF) says that he was a crucial liaison between the Taliban and other Islamic fundamentalist groups while he was deputy intelligence minister. But the 2008 report also said he was holding out information he had on other top al Qaeda and Taliban leaders during interrogations.

Khairkhwa, a former Taliban governor of Herat, was considered by the Pentagon’s 2008 dossier to be a likely heroin trafficker (PDF). That dossier also says he likely participated in meetings with Iranian officials after 9-11 to help plot attacks on U.S. forces following the invasion.
Iran has worked in some cases with the government that has replaced the Taliban in Afghanistan, but also has been accused by the U.S. military of supplying the Taliban and other insurgent groups with roadside bombs known as improvised explosive devices of IEDs.

Nabi held several military leadership posts for the Taliban and helped organize the al Qaeda/Taliban militias that fought against U.S. and coalition troops in the first year of the war, according to this Pentagon dossier (PDF).