I've had a habit over the years of putting numbers like that in the context of a military organization, and 172 is about the size of a slightly understrength infantry company. IOW, in terrorist terms, it's a fair number of people. Some of the information gleaned from news reports thus far:
According to a statement issued by the Saudi Ministry of Interior on Friday, Saudi security forces broke up more than seven jihadist cells that had been engaged in an array of activities against the authorities. The statement did not identify al-Qaeda by name, but described the suspects in typical official codewords for the organization, such as "deviant group" and those who had "adopted the takfiri thought [judging Muslims as infidels] toward Arab and Islamic peoples, governments and leaders."
7 cells in an Arabic country in a state of readiness which only required a "go". You have to assume, given the number arrested, that Saudi intelligence/law enforcement had been on to this for some time. And although initial reports from the Saudi government didn't name al Qaeda specfically, an interior ministry spokesman later did:
Mansour al-Turki, the Interior Ministry spokesman, said the group of 172 Islamic extremists "are carriers of al-Qaida ideology, working on achieving al-Qaida goals, which is to take over the society."
The round up, as mentioned, was significant in size:
The key objectives of these cells, it said, were suicide attacks against Saudi oil installations, public figures and military bases inside and outside the countries. The ministry said that one of the cells had sent recruits to an unspecified foreign country to receive aviation training for use in suicide attacks, copying the operational method of the 9/11 attacks in the U.S.
It isn't clear yet how they planned on using those who were trained to fly: commercial or civilian aviation. However, apparently many of the targets have been identified:
Al-Turki told The AP that the militants planned to use the planes "like car bombs ... to use the aircraft as a tool to carry out suicide operations." He said the targets also included Saudi military bases, which he said the militants had no other way of reaching but "through these means" of blowing up an aircraft.
Apparently many of these terrorist were "blooded" in Iraq, Afghanistan, Pakistan and possibly Somalia. As the article notes, that was the jihadist MO in the '80s as well:
Information released by the Interior Ministry revealed that three of the cells involved had been using Iraq as a theater of terror operations as well as a training and staging area for attacks against Saudi Arabia. That may be a case of history repeating itself — Saudi native Osama bin Laden and other Arabs who had participated in the Afghanistan jihad of the '80s later returned to their home countries to fight the authorities during the '90s. One cell of 59 Saudis and non-Saudis sent members to "external training camps" to "participate in regional conflicts" — a reference to Iraq, according to Saudi sources — with the aim of facilitating "their return to the Kingdom to carry out their criminal plans." Another cell was actually formed abroad with the aim of launching attacks in Saudi Arabia and other countries.
Meanwhile, three of the cells were targeting Saudi Arabia's oil installations, apparently with the aim of crippling Saudi oil revenues and causing massive oil price rises to disrupt to global economy.
One of the cells even planned to overthrow Saudi King Abdullah bin Abdulaziz Al Saudi and replace him with an al-Qaeda leader.
So the intent was to cripple the military, attack the oil producing sector and topple the government, replacing it with a fundamentalist regime under al Qaeda leadership.
Another interesting aspect of this was how they funded it:
The Interior Ministry said that a collection of cells consisting of 61 members had duped a large number of people out of "huge amounts of money" in raising funds for its operations, including the training of suicide pilots outside the country. The ministry said that the leader of the group, who was not identified, received baya, or allegiance as an Islamic authority, from its members in a secret ceremony at the Kaaba in Mecca, Islam's holiest site.
The last time that happened was in 1979, when as many as 1,500 Muslim militants led by Juhayman al-Otaibi seized the Grand Mosque in Mecca in a bid to overthrow the Saudi monarchy. Security forces crushed Juhayman's revolt. Nearly three decades later, however, the fire Juhayman started has not yet been extinguished.
Of course, as noted, that seizure was ruthlessly crushed by Saudi forces and the leaders quickly executed.
That's what I'm waiting to see in this case. How quickly these people are brought to trial and, frankly, how the Saudis handle the how "judicial" aspect of this. My guess is heads are going to roll ... literally.
Abd al-Hadi was taken into CIA custody last year, it emerged from US intelligence sources yesterday, in a move which suggests that he was interrogated for months in a “ghost prison” before being transferred to the internment camp in Cuba.
Mr Whitman refused to say when or where he was captured, or by whom. “Abd al-Hadi was trying to return to his native country, Iraq, to manage al-Qaeda’s affairs and possibly focus on operations outside Iraq against Western targets,” Mr Whitman said.
Yep, a Iraqi major in addam’s army who is a member of AQ, who planned the July London bombings. Yes, just not possible I guess. I see that none of the regaulr mouth pieces of a certain political bent (NYT, LAT, etc) are reporting on it.