Abd al-Hadi al-Iraqi is among the most important figures to have been captured since 9/11 and his detention is a significant blow to Osama bin Laden’s terrorist network.

More than anyone else, it was Abd al-Hadi who rebuilt al-Qaeda after its leadership fled from the US-led invasion of Afghanistan.

Once secured in the tribal areas of Pakistan, he began forging a firm alliance with Abu Musab al-Zarqawi and bringing the jihad in Iraq under the al-Qaeda banner. He ran terror training camps, planned strategy with bin Laden and Ayman al-Zawahiri and directed operations in Afghanistan, Pakistan, Iraq and Europe.

Pakistani intelligence sources said that Abd al-Iraqi had often visited the Bajaur tribal region, one of the main centres of al-Qaeda operations in Pakistan and Afghanistan. US officials said last night that they believed him to be the mastermind behind two attempts in 2002 to assassinate President Pervez Musharraf of Pakistan.

Compared with Khalid Sheikh Mohammed — the planner of the 9/11 atrocities whom he will join in the “high-value detainee programme” in Guantanamo Bay — Abd al-Hadi’s operations were less ambitious but usually more attainable.

Security sources say Abd al-Hadi masterminded a series of plots to carry out suicide attacks in Britain, using young British Muslims including the 7/7 bombers. There have been previous attempts to capture or kill him. In 2004 the Pakistani Army mounted a huge assault on a compound that was thought to be his base. More than 70 people died.

Abd al-Hadi, whose full name is Nashwan Abdulrazaq Abdulbaqi, was born in 1961 in the Kurdish city of Mosul, northern Iraq. He did national service in Saddam Hussein’s Army, rising to the rank of major, but left for Afghanistan in the mid-1980s to join the jihad against the Soviet Union.

His military experience and expertise, as well as his commitment to the Islamist cause, attracted the attention of bin Laden and his fledgling al-Qaeda movement. Abd al-Hadi commanded many of the training camps that were established by al-Qaeda when it returned to Afghanistan after the Taleban seized control there in 1996. After the invasion of Afghanistan, Abd al-Hadi maintained a strong relationship with the Taleban and has used those bonds in the campaign against Western forces in Afghanistan.

In August 2005 he appeared in an al-Qaeda propaganda video that showed militants in Afghanistan — including Europeans, Arabs and other fighters — preparing to attack US troops. In the video Abd al-Hadi said that the US-led wars in Afghanistan and Iraq had created “two fronts” for recruiting terrorists to the cause of global jihad.“Now all the world is united behind Mullah Omar and Sheikh Osama,” he said.

Abd al-Hadi is now locked up in the maximum-security Camp 5 block of Guantanamo Bay, set aside for the most significant terror suspects.

The Pentagon said that Abd al-Hadi had been classified as a “high-value” detainee, along with 14 others. They spend 23 hours a day inside a 7ft (3m by 2m) cell. The classification indicated that US officials believed the capture had a significant effect on al-Qaeda operations and that the prisoner was capable of providing high-quality intelligence.

CNN cited unnamed US officials saying that Abd al-Hadi came into CIA custody after President Bush’s speech last September on the agency’s programme of interrogating high-value prisoners. At that time, the president said, there were “no terrorists” in the CIA programme.

Abd al-Hadi faces a closed-door hearing to determine his status. It will be overseen by a “presiding officer” who must determine if he can be designated as an “unlawful enemy combatant”. If he is given this classification, then the US does not have to charge him or try him.

The US Rewards For Justice programme described Abd al-Hadi as one of bin Laden’s “top global deputies” who remained in contact with his emir. A reward of $1 million (£500,000) was offered for his capture. The reality is that his arrest was of much greater value.

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