September 11 attacks:Attackers and their background

Within hours of the attacks, the FBI was able to determine the names and in many cases the personal details of the suspected pilots and hijackers. Mohamed Atta, from Egypt, was the ringleader of the 19 hijackers and one of the pilots. Atta died in the attack along with the other hijackers, but his luggage, which did not make the connection from his Portland flight onto Flight 11, contained papers that revealed the identity of all 19 hijackers (all men), and other important clues about their plans, motives, and backgrounds. By midday, the National Security Agency had intercepted communications that pointed to Osama bin Laden, as did German intelligence agencies.

On September 27, 2001, the FBI released photos of the 19 hijackers, along with information about the possible nationalities and aliases of many. Fifteen of the hijackers were from Saudi Arabia, two from the United Arab Emirates, one from Egypt (Atta), and one from Lebanon.

The FBI investigation into the attacks, code named operation PENTTBOM, was the largest and most complex investigation in the history of the FBI, involving over 7,000 special agents. The United States government determined that al-Qaeda, headed by Osama bin Laden, bore responsibility for the attacks, with the FBI stating "evidence linking al-Qaeda and bin Laden to the attacks of September 11 is clear and irrefutable". The Government of the United Kingdom reached the same conclusion regarding al-Qaeda and Osama bin Laden's culpability for the 11 September attacks.

Author Laurie Mylroie, writing in the conservative political magazine The American Spectator in 2006, argues that Khalid Sheikh Mohammed and his family are the primary architects of 9/11 and similar attacks, and that Khalid Sheikh Mohammed's association with Osama bin Laden is secondary and that al-Qaeda's claim of responsibility for the attack is after the fact and opportunistic. Angelo Codevilla, of the same magazine, agrees with Mylroie, comparing Osama bin Laden to Elvis Presley. In an opposing point of view, former CIA officer Robert Baer, writing in Time magazine in 2007, asserts that George W. Bush Administration's publicizing of Khalid Sheikh Mohammed's claims of responsibility for 9/11 and numerous other acts was a mendacious attempt to claim that all of the significant actors in 9/11 had been caught.

al-Qaeda and blowback
The origins of al-Qaeda can be traced back to 1979 when the Soviet Union invaded Afghanistan. Soon after the invasion, Osama bin Laden traveled to Afghanistan where he helped organize Arab mujahideen and established the Maktab al-Khidamat (MAK) organization to resist the Soviets. During the war with the Soviet Union, Bin Laden and his fighters received American and Saudi funding, with American and most Saudi funds funneled through the ISI, Pakistan's intelligence service. In 1989, as the Soviets withdrew, MAK was transformed into a "rapid reaction force" in jihad against governments across the Muslim world. Under the guidance of Ayman al-Zawahiri, Osama bin Laden became more radical. In 1996, bin Laden issued his first fatwā, which called for American soldiers to leave Saudi Arabia.

In a second fatwā issued in 1998, bin Laden outlined his objections to American foreign policy towards Israel, as well as the continued presence of American troops in Saudi Arabia after the Gulf War. Bin Laden used Islamic texts to exhort violent action against American military and citizenry until the stated grievances are reversed, noting "ulema have throughout Islamic history unanimously agreed that the jihad is an individual duty if the enemy destroys the Muslim countries."

Planning of the attacks
The idea for the September 11 plot came from Khalid Sheikh Mohammed, who first presented the idea to Osama bin Laden in 1996. At that point, Bin Laden and al-Qaeda were in a period of transition, having just relocated back to Afghanistan from Sudan. The 1998 African Embassy bombings and Bin Laden's 1998 fatwā marked a turning point, with bin Laden intent on attacking the United States. In December 1998, the Director of Central Intelligence Counterterrorist Center reported to the president that al-Qaeda was preparing for attacks in the USA, including the training of personnel to hijack aircraft.

In late 1998 or early 1999, bin Laden gave approval for Mohammed to go forward with organizing the plot. A series of meetings occurred in spring of 1999, involving Khalid Sheikh Mohammed, Osama bin Laden, and his deputy Mohammed Atef. Mohammed provided operational support for the plot, including target selections and helping arrange travel for the hijackers. Bin Laden overruled Mohammed, rejecting some potential targets such as the U.S. Bank Tower in Los Angeles because "there was not enough time to prepare for such an operation".

Bin Laden provided leadership for the plot, along with financial support, and was involved in selecting participants for the plot. Bin Laden initially selected Nawaf al-Hazmi and Khalid al-Mihdhar, both experienced jihadists who fought in Bosnia. Hazmi and Mihdhar arrived in the United States in mid-January 2000, after traveling to Malaysia to attend the Kuala Lumpur al-Qaeda Summit. In spring 2000, Hazmi and Mihdhar took flying lessons in San Diego, California, but both spoke little English, did not do well with flying lessons, and eventually served as "muscle" hijackers.

In late 1999, a group of men from Hamburg, Germany arrived in Afghanistan, including Mohamed Atta, Marwan al-Shehhi, Ziad Jarrah, and Ramzi Binalshibh. Bin Laden selected these men for the plot, as they were educated, could speak English, and had experience living in the west. New recruits were routinely screened for special skills, which allowed Al Qaeda leaders to also identify Hani Hanjour, who already had a commercial pilot's license, for the plot.

Hanjour arrived in San Diego on December 8, 2000, joining Hazmi. They soon left for Arizona, where Hanjour took refresher training. Marwan al-Shehhi arrived at the end of May 2000, while Atta arrived on June 3, 2000, and Jarrah arrived on June 27, 2000. Binalshibh applied several times for a visa to the United States, but as a Yemeni, he was rejected out of concerns he would overstay his visa and remain as an illegal immigrant. Binalshibh remained in Hamburg, providing coordination between Atta and Khalid Sheikh Mohammed. The three Hamburg cell members all took pilot training in south Florida.

In spring 2001, the muscle hijackers began arriving in the United States. In July 2001, Atta met with Binalshibh in Spain, where they coordinated details of the plot, including final target selection. Binalshibh also passed along Bin Laden's wish for the attacks to be carried out as soon as possible.

Osama bin Laden
Osama bin Laden's declaration of a holy war against the United States, and a fatwā signed by bin Laden and others calling for the killing of American civilians in 1998, are seen by investigators as evidence of his motivation to commit such acts.

Bin Laden initially denied, but later admitted, involvement in the incidents. On September 16, 2001, bin Laden denied any involvement with the attacks by reading a statement which was broadcast by the Al Jazeera satellite channel: "I stress that I have not carried out this act, which appears to have been carried out by individuals with their own motivation." This denial was broadcast on U.S. news networks and worldwide.

In November 2001, U.S. forces recovered a videotape from a destroyed house in Jalalabad, Afghanistan, in which Osama bin Laden is talking to Khaled al-Harbi. In the tape, bin Laden admits foreknowledge of the attacks. The tape was broadcast on various news networks from December 13, 2001. His distorted appearance on the tape has been attributed to tape transfer artifact. The detailed timeline of Bin Laden's having prior knowledge were revealed in a September 2002 interview documentary-maker Yosri Fouda conducted with Khalid Sheikh Mohammed and Ramzi Binalshibh: the decision to launch a "martyrdom operation inside America" was made by Al Qaeda's military committee in early 1999; Atta, after deciding on the date (9/11/01) for the attacks, informed Binalshibh of this date on August 29, 2001, and Bin Laden was given this information on September 6, 2001.

On December 27, 2001, a second bin Laden video was released. In the video, he states, "Terrorism against America deserves to be praised because it was a response to injustice, aimed at forcing America to stop its support for Israel, which kills our people", but he stopped short of admitting responsibility for the attacks.

Shortly before the U.S. presidential election in 2004, in a taped statement, bin Laden publicly acknowledged al-Qaeda's involvement in the attacks on the U.S. and admitted his direct link to the attacks. He said that the attacks were carried out because "we are free...and want to regain freedom for our nation. As you undermine our security we undermine yours." Osama bin Laden says he had personally directed his followers to attack the World Trade Center In the video, he says, "We had agreed with the Commander-General Muhammad Atta, Allah have mercy on him, that all the operations should be carried out within 20 minutes, before Bush and his administration notice." Another video obtained by Al Jazeera in September 2006 shows Osama bin Laden with Ramzi Binalshibh, as well as two hijackers, Hamza al-Ghamdi and Wail al-Shehri, as they make preparations for the attacks.

Khalid Sheikh Mohammed
The journalist Yosri Fouda of the Arabic television channel Al Jazeera reported that in April 2002, Khalid Sheikh Mohammed admitted his involvement, along with Ramzi Binalshibh, in the "Holy Tuesday operation". The 9/11 Commission Report determined that the animosity towards the United States felt by Khalid Sheikh Mohammed, the "principal architect" of the 9/11 attacks, stemmed "not from his experiences there as a student, but rather from his violent disagreement with U.S. foreign policy favoring Israel".

Mohamed Atta shared this motivation. Ralph Bodenstein, a former classmate of Atta described him as "most imbued actually about... U.S. protection of these Israeli politics in the region". Abdulaziz al-Omari, a hijacker aboard Flight 11 with Mohamed Atta, said in his video will, "My work is a message those who heard me and to all those who saw me at the same time it is a message to the infidels that you should leave the Arabian peninsula defeated and stop giving a hand of help to the coward Jews in Palestine."

Khalid Sheikh Mohammed was also an adviser and financier of a 1993 bombing, also on the World Trade Center. He is also the uncle of Ramzi Yousef, the lead bomber in that attack.

Khalid Sheikh Mohammed was arrested on March 1, 2003 in Rawalpindi, Pakistan by Pakistani security officials working with the CIA, and is currently being held at Guantanamo Bay. During U.S. hearings in March 2007 Sheikh Mohammed again confessed his responsibility for the attacks, saying "I was responsible for the 9/11 operation, from A to Z." Mohammed made the confession after being subject to waterboarding. In November 2009, U.S. Attorney General Eric Holder announced that Mohammed and four accused co-conspirators will be transferred from Guantanamo Bay, Cuba to stand trial in civilian court near Ground Zero in New York. No trial date was given. Holder expressed confidence that the defendants would get a fair trial that was "open to the public and open to the world".

Other al-Qaeda members
In "Substitution for Testimony of Khalid Sheikh Mohammed" from the trial of Zacarias Moussaoui, five people are identified as having been completely aware of the operation's details. They are Osama bin Laden, Khalid Sheikh Mohammed, Ramzi Binalshibh, Abu Turab al-Urduni and Mohammed Atef. To date, only peripheral figures have been tried or convicted for the attacks. Bin Laden has not yet been formally indicted for the attacks.

On September 26, 2005, the Spanish high court directed by judge Baltasar Garzón sentenced Abu Dahdah to 27 years of imprisonment for conspiracy on the 9/11 attacks and being a member of the terrorist organization al-Qaeda. At the same time, another 17 al-Qaeda members were sentenced to penalties of between six and eleven years. On February 16, 2006, the Spanish Supreme Court reduced the Abu Dahdah penalty to 12 years because it considered that his participation in the conspiracy was not proven.

Motives
The motives for the attacks include the presence of the U.S. in Saudi Arabia, the support of Israel by the U.S., and the sanctions against Iraq. These motives were explicitly stated by Al-Qaeda in proclamations before the attacks, including the fatwā of August 1996, and a shorter fatwa published in February 1998. After the attacks, bin Laden and al-Zawahiri published additional video tapes and audio tapes, some of which repeated those reasons for the attacks. Two particularly important publications were bin Laden's 2002 "Letter to America", and a 2004 video tape by bin Laden. In addition to direct pronouncements by bin Laden and Al-Qaeda, numerous political analysts have postulated motivations for the attacks.

The continued presence of U.S. troops after the Gulf War in Saudi Arabia was one of the stated motivations behind the September 11th terrorist attacks, the Khobar Towers bombing, as well, the date chosen for the 1998 United States embassy bombings (August 7), was eight years to the day that American troops were sent to Saudi Arabia. Bin Laden interpreted the Prophet Muhammad as banning the "permanent presence of infidels in Arabia". In 1996, Bin Laden issued a fatwa, calling for American troops to get out of Saudi Arabia. In the 1998 fatwa, Al-Qaeda wrote " for over seven years the United States has been occupying the lands of Islam in the holiest of places, the Arabian Peninsula, plundering its riches, dictating to its rulers, humiliating its people, terrorizing its neighbors, and turning its bases in the Peninsula into a spearhead through which to fight the neighboring Muslim peoples." In the December 1999 interview with Rahimullah Yusufzai, bin Laden said he felt that Americans were "too near to Mecca" and considered this a provocation to the entire Muslim world.

In his November 2002 "Letter to America", Bin Laden described the United States' support of Israel as a motivation: "The creation and continuation of Israel is one of the greatest crimes, and you are the leaders of its criminals. And of course there is no need to explain and prove the degree of American support for Israel. The creation of Israel is a crime which must be erased. Each and every person whose hands have become polluted in the contribution towards this crime must pay its price, and pay for it heavily." In 2004 and 2010, Bin Laden again repeated the connection between the September 11 attacks and the support of Israel by the United States. Several analysts, including Mearsheimer and Walt, also assert that a motivation for the attacks was the support of Israel by the United States.

In the 1998 fatwa, Al Qaeda identified the Iraq sanctions as a reason to kill Americans: "despite the great devastation inflicted on the Iraqi people by the crusader-Zionist alliance, and despite the huge number of those killed, which has exceeded 1 million... despite all this, the Americans are once against trying to repeat the horrific massacres, as though they are not content with the protracted blockade imposed after the ferocious war or the fragmentation and devastation....On that basis, and in compliance with Allah's order, we issue the following fatwa to all Muslims:The ruling to kill the Americans and their allies—civilians and military—is an individual duty for every Muslim..."

In addition to the motives published by Al Qaeda, analysts have suggested other motives, including humiliation resulting from the Islamic world falling behind the Western world - this discrepancy made especially visible due to recent globalisation. Another speculated motive was the desire to provoke the U.S. into a broader war against the Islamic world, with the hope of motivating more allies to support Al Qaeda.
 * Michael Scott Doran and Peter Bergen have argued that 9/11 was a strategic way to provoke America into a war that incites a pan-Islamisic revolution. Michael Scott Doran argues the attacks are best understood as being part of a religious conflict within the Muslim world. In an essay, |title=somebody-elses-civil-war Somebody Else's Civil War Doran argued that Bin Laden's followers: "consider themselves an island of true believers surrounded by a sea of iniquity".
 * Hoping that U.S. retaliation would unite the faithful against the West, bin Laden sought to spark revolutions in Arab nations and elsewhere. Doran argues the Osama bin Laden videos were attempting to provoke a visceral reaction in the Middle East and ensure that Muslim citizens would react as violently as possible to an increase in U.S. involvement in their region.
 * In The Osama bin Laden I Know, correspondent Peter Bergen argues that the attacks were part of a plan to cause the United States to increase its military and cultural presence in the Middle East, thereby forcing Muslims to confront the idea of a non-Muslim government and establish conservative Islamic governments in the region.