U.S. Officials Believe Al Qaeda's Claim of Responsibility for Attempted Underpants Attack Is Credible

U.S. government experts believe that a statement circulated Monday purporting to come from Al Qaeda's Yemeni affiliate that claimed credit for the attempted Christmas Day bombing of a transatlantic airliner is likely authentic and credible, according to a U.S. national-security official. The official, who asked for anonymity when discussing sensitive information, said that U.S. intelligence analysts believe that the message really did originate with Al Qaeda in the Arabian Peninsula, which the U.S. believes is an Al Qaeda "franchise" that operates in both Yemen and Saudi Arabia.

The official added that U.S. agencies are increasingly willing to believe that Al Qaeda in the Arabian Peninsula really did have something to do with arming and directing would-be airline bomber Umar Farouk Abdulmutallab, whose attack failed when he tried to set off his underpants bomb but it burst into flames rather than exploding.

The message asserted that the apparent attempt was carried out in "direct coordination with the Mujahideen in the Arabian Peninsula" and that it was a direct response to recent U.S.-supported raids on alleged Al Qaeda encampments in Yemen. U.S. officials say that due to at least one serious anomaly they are not taking all of the assertions literally: as we noted yesterday Abdulmutallab reportedly bought his airline ticket before the first recent U.S.-backed strike against Al Qaeda encampments in Yemen, which came on December 17.

U.S. investigators are still examining evidence—some of the key elements coming from statements Abdulmutallab himself reportedly made to U.S. investigators—regarding the extent to which the Yemeni AQ affiliate helped him plan and carry out the failed attack. But they are leaning increasingly to the view that there may have been substantial AQ involvement in the alleged underpants plot. Investigators say they have not confirmed nor disproved allegations that have begun to circulate in the media that one or more Yemeni AQ leaders who helped set up the plot are former detainees who were recently let out of the U.S. terrorism detention camp at Guantánamo, Cuba.

Also, U.S. investigators are looking into possible parallels between the attempted airplane underpants attack and an attack earlier this year in which a notorious Saudi terrorist tried to murder Saudi Arabia's counter-terrorism czar. As Peter Bergen, a respected terrorism expert, noted on CNN, the explosive used in the August attack on Prince Mohammed bin Nayef, PETN, was the same explosive apparently used in the failed underpants bombing. The alleged unsuccessful Saudi assasin, Abdullah Hassan al-Asiri, who apparently secreted a PETN device up his rectum, had taken refuge in Yemen before returning to Saudi Arabia and trying to blow up the prince.

A U.S. official noted, however, that while they used similar ingredients, the bombs used in these incidents may well have been rigged with different kinds of detonators, leaving doubt as to whether the attacks are directly linked or only eerily similar.