It's difficult to exaggerate the value of the sting operation that foiled Al Qaeda's latest underwear bomb plot. On Tuesday night, U.S. officials revealed that a Saudi agent working with the CIA infiltrated Al Qaeda's branch in Yemen and volunteered to blow himself up on a U.S.-bound jetliner. The agent gained the trust of the terrorist cell, obtained the group's latest underwear bomb and delivered it to CIA officials intact. Here's why sting is such an intelligence coup:

Snagging the bomb intact. Typically, when U.S. officials uncover Al Qaeda's bombs it's after they've been triggered, making it more difficult to understand how they work. The genius of this operation is the CIA retrieved the bomb intact, which we now know was very sophisticated. This morning, NPR's Dina Temple-Raston learned that this bomb was much more sophisticated than the 2009 underwear bomb. "Sources tell us it was a really form-fitting bomb that would've been hard for Airport security to spot even with a pat-down," she reports. "To give you an idea of how it's different from the 2009 bomb, the Christmas day underwar bomb was put in Yemeni boxer shorts that are kind of loose fitting. This bomb was put in the equivalent of briefs so it was ... form-fitting and harder to see."

Learning about bin Laden's Al Qaeda.  There are many offshoots of Al Qaeda but the one in Yemen, which was infiltrated, is the most fearsome, former FBI interrogator Ali Soufan told PBS News Hour last night. "Al-Qaida in the Arabian Peninsula is the closest to bin Laden's version of al-Qaida. All these individuals were with bin Laden in Afghanistan, served with bin Laden. They are not one of these al-Qaida groups that were franchised after 9/11," he said. He stressed that it's a "great success" that officials have a window into the Al Qaeda branch because they won't be giving up anytime soon. "They are very dangerous," he said, "And I think we should keep in mind that they will always try to accomplish their goal. I mean, al-Qaida tried to do a shoe bomb and then an underwear bomb, a printer bomb, and they will continue to work hard to inflict damage to the United States."

Getting closer to Ibrahim Hassan al-Asiri. U.S. officials have confirmed that the sophisticated underwear bomb was created by infamous Al Qaeda bombmaker Ibrahim Hassan al-Asiri (pictured above), a man who The Washington Post says represents the CIA's worst fears. "He has dispatched his own brother to death, hiding a bomb on him before he crossed into Saudi Arabia to target the kingdom’s chief counterterrorism official," reports the paper. "He has tried to attack the United States three times in the past three years, building small, sophisticated and hard-to-detect devices in his workshop in the rugged terrain of southern Yemen ... Only 30 years old, he represents the CIA’s worst fears: a highly skilled terrorist determined to attack the United States." The fact that the double agent was able to report back information about him is invaluable. “Asiri is an evil genius," Rep. Peter King tells the paper.
 
The death of Fahd al-Quso. One of the intelligence coups from the double agent has already paid off. According to reports, the Saudi agent was able to give the CIA information that led to the killing of Fahd Mohammad Ahmed Al-Quso. "The al Qaeda terrorist killed in a CIA drone missile strike in Shabwa, Yemen this past weekend was one of the FBI's Ten Most Wanted Terrorists," reports CBS News. "[He] was most notorious for being an alleged planner of the terrorist attack on the USS Cole that killed 17 American sailors and blew a 40-foot hole in the side of the warship 12 years ago."