The Washington Post reports: For al-Qaeda’s affiliate in Yemen, the volunteer seemed ideal. He was willing to die in a suicide operation, and he had travel papers that would allow him to board a U.S.-bound flight.

It was a perfect dangle, in the parlance of spycraft, and al-Qaeda in the Arabian Peninsula took the bait.

The group’s bombmaker fitted the man with a new version of a nonmetallic “underwear bomb.” What he didn’t know was that the would-be martyr was an agent run by Saudi Arabia. And the man turned the device over to his Saudi handlers inside Yemen.

The Saudis flew the bomb out of the country on a noncommercial jet and handed it over to American officials in an unidentified third country, according to Mustafa Alani, director of security and defense studies at the Gulf Research Center in Jiddah, Saudi Arabia, who has close contacts with the kingdom’s intelligence and counterterrorism agencies. A U.S. official confirmed aspects of his account.

The informant was one of several operatives sent into Yemen over the past two years with Western passports and other documents designed to attract the attention of a terrorist group that is determined to attack the United States, U.S. and Western intelligence officials said Wednesday.

One official described the effort to disrupt the airline plot as part of a broader use of operatives with “clean skins” who can pass themselves off as militants capable of traveling into Europe or the United States.

As part of the effort, the Saudis have used fledgling al-Qaeda operatives who were temporarily detained, as well as individuals who have entered the country’s rehabilitation program, which seeks to turn militants against terrorist groups.

The effort has focused on flipping low-level and aspiring jihadis, according to a former U.S. intelligence official familiar with the operation, which was revealed in news reports Monday.

It’s worth remembering that al Qaeada has demonstrated that it can be as adept in the art of deception as are the intelligence agencies. As the Washington Post reported in January, 2010:

The suicide bomber who killed seven CIA operatives in Afghanistan last week was a Jordanian informant who lured intelligence officers into a trap by promising new information about al-Qaeda’s top leadership, former U.S. government officials said Monday.

The attacker, a physician-turned-mole, had been recruited to infiltrate al-Qaeda’s senior circles and had gained the trust of his CIA and Jordanian handlers with a stream of useful intelligence leads, according to two former senior officials briefed on the agency’s internal investigation. His track record as an informant apparently allowed him to enter a key CIA post without a thorough search, the sources said.

The bomber, identified as Humam Khalil Abu-Mulal al-Balawi, was standing just outside an agency building on the base Wednesday when he exploded a bomb hidden under his clothes, killing the seven Americans along with a Jordanian officer who had been assigned to work with him. Six CIA operatives were wounded.

The agency has declined to publicly identify the victims, a mix of career officers and contractors with backgrounds ranging from law enforcement to military Special Forces.

Details about the suicide bomber’s identity provided jarring insight into how a vital intelligence post in eastern Afghanistan was penetrated in the deadliest attack on the CIA in more than 25 years. Initial reports suggested that the bomber was an Afghan soldier or perhaps a local informant who had been brought onto the base for debriefing.

Instead, the new evidence points to a carefully planned act of deception by a trusted operative from a country closely allied with the United States in the fight against al-Qaeda. U.S. and Jordanian officials had come to regard Balawi as trustworthy, former officials said, despite a history of support for Islamist extremism — a point of view he appeared to endorse in an interview with an al-Qaeda-affiliated publication as recently as this past fall.

“He was someone who had already worked with us,” said a former U.S. counterterrorism officer who discussed the ongoing investigation on the condition of anonymity. The official said Balawi had been jointly managed by U.S. and Jordanian agencies and had provided “actionable intelligence” over several weeks of undercover work along the Afghanistan-Pakistan border.