Osama Bin Laden Born
Born in Jeddah, Saudi Arabia, his family originally came from Yemen.
Office of Services Established
Sheik Abdullah Azzam, a Palestinian religious scholar, establishes the Makhtab al Khadimat — the Office of Services — in Peshawar, Pakistan to recruit an Islamic army to fight the Soviets in Afghanistan. Osama bin Laden provides financial support to Azzam’s organization.
Bin Laden Sets Up Camp, Builds Ties
Bin Laden establishes Al Masadah («The Lion’s Den»), a training camp for Persian Gulf Arabs. Bin Laden begins associating with Egyptian radicals — who, unlike Sheik Abdullah Azzam, advocate a global jihad beyond Afghanistan — and befriends Dr. Ayman al-Zawahiri of the Egyptian Islamic Jihad.
Office of Services Reaches U.S.
The journal published by the Office of Services is distributed in the U.S. by the Islamic Center of Tucson, Arizona.
Al Qaeda Established
Osama bin Laden — along with Muhammad Atef and Abu Ubaidah al Banshiri — founds Al Qaeda («The Base»). The organization operates out of Afghanistan and Peshawar, Pakistan.
Read more about Al Qaeda’s establishment in the U.S. indictment of Osama bin Laden.
Battle for Control of Office of Services
After a car bomb kills Sheik Abdullah Azzam, a battle for control of the Office of Services breaks out between those who believe the jihad should focus on the creation of an Islamic state in Afghanistan, and extremists sympathetic to Osama bin Laden, who want to expand the struggle worldwide. The extremist faction eventually takes control.
Oklahoma Meeting of Future Terrorists
At a conference of Muslims held in Oklahoma City, Wadih el-Hage, a U.S. citizen later convicted in the 1998 U.S. embassy bombings trial, meets with Egyptian Mahmud Abuhalima, who is later convicted for his role in the 1993 World Trade Center Bombing. Abuhalima later tries to buy guns from el-Hage.
For more details on el-Hage’s Al Qaeda connections, read FRONTLINE’s «A Portrait of Wadih el-Hage».
Soviet Forces Withdraw from Afghanistan
The Soviets’ humiliating defeat by mujahedeen forces in their 10-year long war inspires Osama bin Laden and other Islamic radicals to believe their victory in Afghanistan can be replicated around the world. At the end of the war, many of the «Afghan Arabs,» as the radicals were called, returned home. Osama bin Laden returns to Saudi Arabia.
Bomb Manuals, Photos Discovered
During an investigation into the assassination of the right-wing rabbi Meir Kahane, authorities discover bomb manuals and photographs of the World Trade Center and the Empire State Building in the apartment of an Egyptian, El-Sayyid Nosair. Nosair reportedly is an associate of Wadih el-Hage.
It is later learned that Nosair’s legal bills in the WTC bombing trial were paid for by bin Laden. This is the earliest known intelligence information linking bin Laden to terrorists.
Bin Laden Flees to Sudan
Bin Laden leaves Saudi Arabia and travels to Afghanistan with some of his supporters. By 1992, they finally settle in Khartoum, Sudan.
Read more on FRONTLINE’s «Hunting bin Laden» chronology.
Bin Laden Organizes Attacks on U.N. Forces in Somalia
According to a document released by the British government after the Sept. 11 attacks, between 1992 and 1993, Mohammed Atef, an Egyptian aide to bin Laden, travels frequently to Somalia to organize violent attacks on U.S. and U.N. troops stationed there. After each trip he reports back to bin Laden in Khartoum.
Expanding the Terror Network
According to the U.S. indictment of bin Laden, between 1992 and 1996 Al Qaeda makes overtures to Iran and Hezbollah to take part in a global war against the U.S. The indictment alleges that Mamdouh Mahmud Salim, an Al Qaeda leader, met with Iranian officials and that Al Qaeda sent members to Lebanon to receive training from members of Hezbollah. American officials also claim that around this time bin Laden’s group begins an effort to secure components for chemical and nuclear weapons.
Dec. 29, 1992
Al Qaeda’s First Attack
In an apparent plot to kill U.S. servicemen headed to Somalia, a bomb explodes at a hotel in Aden, Yemen and kills two Austrian tourists. Two Yemeni Muslims — who had been trained in Afghanistan — are injured and later arrested. Intelligence officials believe this is Al Qaeda’s first attack.
The Associated Press later reports that two of the Yemenis detained for the 2000 attack on the USS Cole were involved both in this 1992 Aden bombing, and a series of other attacks in 1993.
Feb. 26, 1993
World Trade Center Bombing
A truck bomb explodes in the parking garage of the World Trade Center (WTC) killing six and injuring hundreds. Investigators discover the suspects have links to a network of Islamic extremists. Several people eventually convicted in the bombing are linked to the Office of Service’s Al Kifah Center in Brooklyn; four of these men are connected to Sheik Omar Abdel Rahman. Rahman, a blind Egyptian cleric who was the spiritual leader of the Egyptian Islamic Jihad, is later convicted of conspiracy for his involvement in a plot to blow up New York City landmarks. He is sentenced to life in prison.
Investigators charge Ramzi Yousef as the mastermind behind the WTC bombing and begin a worldwide manhunt. They discover immigration officials had already detained Ahmed Ajaj, a Yousef associate, when he entered the U.S. carrying terrorist training manuals.
Osama bin Laden’s name surfaces during the 1993 WTC investigation as a financier of the Office of Services. His name is also found on a list of individuals who was called from a safe house used by the conspirators. During the WTC bombing trial, bin Laden’s name appears on a list of potential unindicted co-conspirators, but Al Qaeda is never mentioned.
Final Training of Somali Forces
According to a document published by the British government, Muhammad Atef, Saif al Adel and other members of Al Qaeda return to Somalia to train Somali forces to attack U.N. troops.
Future Bojinka Conspirators Meet
Pakistani Abdul Hakim Murad — later convicted for his role in the 1995 Bojinka («Big Bang») plot to blow up twelve airliners — meets Khalid Shaikh Mohammed at Mohammed’s house in Karachi, Pakistan while visiting with Ramzi Yousef. Murad would later tell investigators that Khalid Shaikh Mohammed — suspected of helping to plan the Sept. 11 attacks — had an “intense” interest in pilot training.
Oct. 3-4, 1993
«Black Hawk Down»
Eighteen American soldiers are attacked and killed in Mogadishu, Somalia. A U.S. indictment later charges bin Laden and his followers with training the attackers.
Read more about the incident on FRONTLINE’s «Ambush in Mogadishu» Web site.
Al Qaeda Contemplates Nairobi Attack
Members of an Al Qaeda cell in Kenya discuss attacking the U.S. embassy there. Ali Mohamed, a U.S. citizen, later admits to investigators that he took photographs and sketches of the embassy and presented them to bin Laden in the Sudan.
Air France Flight Hijacked
A group of Algerian hijackers seize an Air France flight headed for Paris. The crisis ends after French commandos storm the plane. According to some French investigators, the hijackers planned to blow up the plane above Paris or crash it into the Eiffel Tower.
Ramzi Yousef Hides
Ramzi Yousef, suspected mastermind of the 1993 WTC attack, hides out in the Philippines with Khalid Shaikh Mohammed, believed to be his uncle. The two reportedly plan a number of potential terrorist attacks.
Bin Laden Funds Sudan Terrorist Camps
By January 1994, bin Laden is reportedly supporting at least three Sudan training camps.
July 11, 1994
Al Qaeda’s London Office
According to a later U.S. indictment, bin Laden sets up a media information office in London which will serve as a message center and provide cover for Al Qaeda operations. The center is run by Khalid al-Fawwaz.
Marrakesh Hotel Attack
In Marrakesh, Morocco, two Spaniards are killed when three French Muslims open fire on tourists in a hotel lobby. European investigators reportedly discover phone calls between the suspects and the Office of Services. They also start to uncover a network of Afghan jihad war veterans in Europe.
Konsojaya Established in Malaysia
Investigators come to suspect that a company named Konsojaya is a front for funneling money from bin Laden to regional operatives. Wali Khan Amin Shah, a Pakistani, and an Indonesian cleric named Riduan Isamuddin (AKA «Hambali») established the company. A number of phone calls are made from Konsojoya offices to Mohammed Khalifa, bin Laden’s brother-in-law, who allegedly ran a charity front for Al Qaeda. The Hambali connection to this group is only discovered after Sept. 11.
2004 Update: «Hambali» now in U.S. custody – see details.
Bojinka Plot — A Test Run
Ramzi Yousef plants a small bomb on a Philippine Airlines plane. The bomb explodes during the second leg of the trip and kills a Japanese businessman. Authorities later discover the bombing is a test run for the planned Bojinka attack.
Bojinka Plot Discovered
Following an explosion in a Manila apartment, Philippine police uncover a plot — code-named Bojinka or “Big Bang” — to blow up 12 airplanes bound for the U.S. Authorities arrest Abdul Hakim Murad, a Pakistani who is an associate of Ramzi Yousef. Yousef flees to Pakistan.
Investigators also discover that Khalid Shaikh Mohammed had visited the apartment frequently. His name is found on documents inside a computer that contain details of the Bojinka plot.
Jan. 20, 1995
Planes as Weapons
In the Bojinka investigation, Manila police interview Abdul Hakim Murad. According to their report, Murad describes his discussions with Ramzi Yousef about hijacking a commercial aircraft and flying it into the headquarters of the CIA.
Yousef and Murad also reportedly discuss the idea of using a small airplane loaded with explosives to bomb targets in the U.S.
Feb. 5, 1995
Ramzi Yousef Captured in Pakistan
Just as FBI Agent John O’Neill begins his new job as section chief of the FBI’s Counterterrorism Section, Yousef is located in Pakistan. O’Neill helps coordinate his capture. Afterwards, authorities learn Yousef spent part of the previous three years living in a bin Laden-funded guesthouse.
Bin Laden’s Letter to King Fahd
Bin Laden sends an open letter to King Fahd of Saudi Arabia calling for a campaign against U.S. forces in Saudi Arabia.
Bojinka Plotter Arrested
Wali Khan Amin Shah is arrested in Malaysia and rendered to the United States. He is later convicted for his role in the Bojinka plot.
Authorities Focus In On Bin Laden
The U.S. State Department issues a dossier on bin Laden that claims he is a financier of radical Islamic causes and connects him to the 1992 hotel bombing in Aden, Yemen and the training of the Somalis who attacked U.S. troops in Mogadishu. At the same time, a grand jury investigation of Osama bin Laden is initiated in New York.
Station «Alex» Confirms Scale of Al Qaeda
The FBI and CIA create a joint station, code-named “Alex,” with the mission of tracking down bin Laden. Richard Clarke would later tell FRONTLINE that with the establishment of Station Alex, “We were able over the course of about 18 months to go from thinking there was a bin Laden network to seeing it in 56 countries.”
Sudan Expels Bin Laden
Under international pressure, Sudan expels bin Laden. He and his followers return to Afghanistan.
An Al Qaeda Informer
Jamal Ahmed al-Fadl leaves Al Qaeda after he’s discovered embezzling money from the organization. Al-Fadl begins cooperating with the U.S., providing information on Al Qaeda’s organization and how it operates.
June 25, 1996
Khobar Towers Bombing, Dhahran, Saudi Arabia
Nineteen American soldiers are killed and 500 people injured in the bombing. Investigators will eventually conclude that the most likely scenario is that the Iranian government commissioned Saudi Hezbollah terrorists to carry out the attack. [See Richard Clarke interview.] Others, however, are convinced bin Laden played some role in the attack.
Sept. 5, 1996
Ramzi Ahmed Yousef, Abdul Hakim Murad, and Wali Khan Amin Shah are convicted for their role in the Bojinka plot.
May 22, 1997
Terrorists Reported To Be Operating in U.S.
The Associated Press reports that senior FBI officials have determined terrorist groups are operating in America. The AP quotes John O’Neill, who is now special agent in charge of the national security division in New York as saying, “Almost every one of these groups has a presence in the United States today. A lot of these groups now have the capacity and the support infrastructure in the United States to attack us here if they choose to.”
Aug. 21, 1997
Evidence of Nairobi Al Qaeda Cell
Police search Wadih el-Hage’s home in Nairobi, Kenya. On his computer they discover documents, which outline the presence of an Al Qaeda cell in Nairobi. Read more on FRONTLINE’s «Hunting bin Laden: Warnings to the FBI»]
After the raid, el-Hage is questioned but not detained, and he returns to America. In the fall, el-Hage denies his involvement in terrorism to a New York grand jury.
Feb. 23, 1998
Al Qaeda Calls for Killing Americans
Bin Laden and Dr. Ayman al-Zawahiri issue a declaration with other extremist groups calling on Muslims to kill Americans anywhere in the world.
Read their statement on FRONTLINE’s «Hunting bin Laden» chronology.
June 8, 1998
Bin Laden Indicted
A U.S. grand jury issues a sealed indictment charging bin Laden with conspiracy to attack “defense utilities of the United States.” The indictment alleges bin Laden is involved in the October 1993 attack on U.S. soldiers in Somalia.
June 10, 1998
Interview with Bin Laden
John Miller of ABC News interviews bin Laden in his mountaintop camp in Afghanistan. During the interview bin Laden admits to knowing Wali Khan Amin Shah, one of the Bojinka plotters, but denies having met Ramzi Yousef. He also denies knowledge of the “Bojinka plot” or a related plot to assassinate Clinton.
Watch the interview on FRONTLINE’s “Hunting bin Laden” Web site.
FAA Warns of Hijackings
The Federal Aviation Administration warns airlines to be on a “high degree of alertness” for possible hijackings by Al Qaeda.
Aug. 6, 1998
Egyptian Jihad’s Warning
The group, led by Dr. Ayman al-Zawahiri, warns of a “message” they will be sending to Americans, “which we hope they read with care, because we will write it, with God’s help, in a language they will understand.”
Aug. 7, 1998
Bombing of U.S. Embassies
American embassies in Nairobi, Kenya and Dar es Salaam, Tanzania are bombed almost simultaneously. The Kenya bombing kills 213 and injures 4,500; the Dar es Salaam bombing kills 11 and injures 85. One of the bombers, Mohamed Al-‘Owhali, a Saudi, flees the scene.
During the investigation, a search of the apartment of Khalid al-Fawwaz, the head of Al Qaeda’s London office, reveals manuals virtually identical to those found in the luggage of Ahmad Ajaj, who was connected to Ramzi Yousef and the 1993 World Trade Center bombing.
Mohamed Sadeek Odeh, a Jordanian who would later be convicted in the embassy bombings trial, is arrested in Pakistan when he tries to enter from Kenya with a fake passport.
A group calling itself the Islamic Army for the Liberation of the Holy Places faxes claims of responsibility for the attack to different media organizations in France, Qatar, and the UAE. According to a document published by the British government, a later investigation reveals that the fax was sent from a telephone number linked to Osama bin Laden.
Progress in Embassy Investigation
Mohamed al-‘Owhali is arrested by Kenyan detectives and confesses to his role in the embassy bombing. Intelligence officials intercept calls between two bin Laden lieutenants implicating them in the embassy bombing. Advisors also warn President Clinton that they have evidence that bin Laden is attempting to purchase weapons of mass destruction.
Aug. 20, 1998
Tomahawk Missile Attack
President Clinton orders Tomahawk missiles fired at a suspected Al Qaeda camp in Afghanistan and a pharmaceutical plant in Sudan, which was suspected of producing chemical weapons for bin Laden. The effectiveness of the strikes is later questioned.
Ali Mohamed Arrested
Ali Mohamed, a U.S. citizen and Al Qaeda member, is arrested in the U.S. Soon after, he begins cooperating and admits he took pictures of the Nairobi embassy and showed them to bin Laden. On Oct. 20, 2000, Mohamed tells a judge, “Bin Laden looked at the picture of the American embassy and pointed to where a truck could go as a suicide bomber.”
Sept. 23, 1998
Links Between East Africa and 1993 WTC Bombing
At a bail hearing for Wadih el-Hage, the U.S. Attorney claims el-Hage had links to El Sayyid Nosair and Mahmud Abouhalima, both convicted in the 1993 World Trade Center bombing.
November 4 1998
Bin Laden Indictment Released
The U.S. government releases its indictment against bin Laden, Muhammad Atef and other members of Al Qaeda.
Khalid Mohammed Visits Germany
Khalid Shaikh Mohammed allegedly visits Hamburg, Germany. After Sept. 11, 2001, U.S. officials suspect he might have met with an Al Qaeda cell in Hamburg.
June 7, 1999
Bin Laden Added to FBI’s «Ten Most Wanted» List
Bin Laden is wanted for murder of U.S. nationals outisde the U.S.; conspiracy to murder U.S. nationals outside the U.S.; and attack on a federal facility resulting in death.
View the FBI’s Most Wanted poster.
Nov. 30, 1999
Jordan Millennium Plot Discovered
Jordanian officials intercept a phone conversation between Abu Zubaydah, a senior Al Qaeda lieutenant, and members of a Jordanian cell planning a plot referred to as “the day of the millennium.” The Jordanians conduct raids and discover explosives and a plan to blow up the Radisson Hotel in Amman and other sites.
Alert: A Malaysia Meeting
The CIA intercepts a phone conversation at a Yemeni house that is an Al Qaeda logistics center, which they had learned about from Mohamed al-‘Owhali, who was convicted in the embassy bombing case. The house is owned by Ahmed Al-Hada, a Yemeni citizen.
The callers discuss an upcoming January 2000 meeting in Kuala Lumpur. Officials learn that Khalid Almidhar, a Yemeni citizen believed to be the son-in-law of Al-Hada, and Nawaf Alhazmi, thought to be a Saudi national, will be attending the meeting. Both Almidhar and Alhazmi will later be hijackers of American Airlines Flight 77 on Sept. 11.
Dec. 14, 1999
Ressam Intercepted at Canadian Boarder
Algerian native Ahmed Ressam is caught entering the U.S. with 130 pounds of explosives at the Canadian border at Port Angeles, Washington. Ressam had links to other Al Qaeda militants and trained in an Afghanistan Al Qaeda camp. Authorities eventually learn his intended target was Los Angeles International Airport.
Read more about Ahmed Ressam on FRONTLINE’s «Trail of a Terrorist» Web site.
The Malaysia Meeting
Several individuals linked to Al Qaeda meet in Kuala Lumpur, Malaysia. At the CIA’s request, Malaysian agents photograph the meeting. Nawaf Alhazmi and Khalid Almidhar (both later hijackers on Sept. 11) attend the meeting at the condo of Yazid Sufaat. Tawfiq bin-Atash (AKA «Khallad») — who once headed bin Laden’s bodyguards and would later become a suspect in the attack on the USS Cole — also attends the meeting.
It is later reported that Riduan Isamuddin (AKA «Hambali»), a militant Islamic preacher — who would eventually be suspected of having had a role in the “Bojinka” plot — also attends the meeting. Officials later also claim Ramzi bin al-Shibh — a former roommate of Sept. 11 hijacker Mohamed Atta — was also photographed at the meeting.
Fahad al-Quso, who is later arrested for his role in the 2000 USS Cole attack, is a suspected “bag man” who carried money to finance the meeting. After Sept. 11, al-Quso denies having attended the Malaysia meeting. However, he would admit he met at other times with bin Atash, Alhazmi and others who were at the Malaysia meeting.
[Note: All the individuals in the photographs are not be identified by intelligence officials until later, and the importance of this Malaysia meeting would not be known until after the Cole investigation began to focus on bin-Atash. It’s unclear at what point the CIA began to recognize the meeting’s importance. Sources would later tell FRONTLINE that FBI agents looking into the Cole attack were not fully told about the meeting or shown pictures of those photographed until the summer of 2001.
Read more about the CIA and FBI communication failure.]
2004 Update: «Hambali» and Tawfiq bin-Atash now in U.S. custody; Fahad Al-Quso now in Yemeni custody – see details.
Jan. 3, 2000
Attack on USS The Sullivans Fails
A cell of Yemeni terrorists try bombing the USS The Sullivans in Yemen’s Aden Harbor, but fail when their overloaded skiff sinks. Investigators do not discover the attempt on the USS The Sullivans until after the USS Cole had been successfully attacked by the same cell in October of 2000.
Jan. 15, 2000
Alhazmi and Almidhar Enter the U.S.
Nawaf Alhazmi and Khalid Almidhar fly into Los Angeles from Bangkok. A later article in Newsweek reports that the CIA knew that Alhazmi was on the plane, but did not know about Almidhar. Neither individual is tracked once they entered the country. Both become suicide hijackers on Sept. 11.
April 17, 2000
FBI Investigates a Flight School
The Phoenix office of the FBI begins to investigate Zakaria Mustapha Soubra, a Phoenix flight school student suspected of having ties to Al Qaeda.
Italy Hears about Planes as Weapons
Between August 2000 and early 2001, Italian investigators begin to record the conversations of Abdulsalam Ali Ali Abdulrahman. According to a later report in the Los Angeles Times, in one of the conversations Abdulrahman tells Abdelkader Moahmoud Es Sayad, an Egyptian suspected terrorist, that planes could be used as weapons against the U.S. According to the article, the FBI was aware of the conversations, but did not receive any reference to planes being used as weapons.
Bin al-Shibh Denied Visa
Ramzi bin al-Shibh, a Yemeni who was Mohamed Atta’s former roommate, applies four times for a visa to enter the U.S., but is denied each time. U.S. officials later allege that he was supposed to take part in the Sept. 11 plot, but at the last minute was slotted to be replaced by Zacarias Moussaoui.
Moussaoui Visits Malaysia
Zacarias Moussaoui, a French national, visits Malaysia and stays at Yazid Sufaat’s condo after Riduan Isamuddin, (AKA «Hambali») asks Sufaat to put up Moussaoui. Sufaat, a Malaysian, also provides Moussaoui with fake identification papers. Also at Hambali’s request, a company owned by Sufaat purchases explosives for an attack on foreign embassies and other targets in Southeast Asia. The plot is foiled after Sept. 11, when a videotape of potential targets is found in an Afghanistan safe house.
Oct. 12, 2000
Attack on the USS Cole — More Revelations
Two men in a skiff pull alongside the American destroyer and detonate an explosive that rips through the hull and kills 17 U.S. sailors. Yemeni authorities quickly capture and start identifying suspects. Among them is Tawfiq bin-Atash, former head of bin Laden’s bodyguards. The CIA eventually comes to realize that bin-Atash had been photographed at the earlier Malaysia meeting and begins to reexamine those photographs. A later document released by the British government would claim that Mohamed al-‘Owhali, convicted for his role in the 1998 embassy bombings, links two of the Cole suspects to the embassy bombings.
2004 Update: Tawfiq bin-Atash now in U.S. custody – see details.
Dec. 8, 2000
Cole Links to Bin Laden
ABC News’ John Miller reports authorities have found a number of connections between the Cole attack and Osama bin Laden, including telephone records of calls between the bombers of the Cole and an Al Qaeda cell in East Africa. Yemeni officials arrest Gamal Al Badawi, a suspect who admits he fought with Al Qaeda forces in Bosnia. Fahad al-Quso, in custody, apparently carried $5,000 from an associate of bin Laden to Cole conspirators. Lastly, Miller reports Yemeni authorities suspect Abdul Al-Nassir both organized the Cole attack and also recruited bombers for the attack on the embassies in East Africa in 1998.
2004 Update: The Fahad Al-Quso case – see details.
FAA Warns of Hijackings
Between January and August of 2001, the Federal Aviation Administration issues 15 advisories to airlines and airports warning that terrorists could try to hijack or destroy American aircraft.
Jan. 24, 2001
«The Brothers Going to America»
Italian authorities record Abdelkader Mahmoud Es Sayed, an imam in Italy, talking about fraudulent documents for “the brothers going to America.”
Jan. 25, 2001
Clarke Warns of Sleeper Cells
Richard Clarke, the National Security Council counterterrorism chief, sends a memo to Deputy National Security Advisor Stephen Hadley warning that Al Qaeda sleeper cells within the U.S. are “a major threat.” Clarke also advocates targeting Al Qaeda training camps in response to the Cole bombing.
Jan. 27, 2001
Cole Links to Al Qaeda Confirmed
The Washington Post reports on this date that investigators in Yemen believe that people in custody are tied closely to Al Qaeda. An anonymous Bush administration official tells The Post, “There is no question that Al Qaeda was involved in this attack.”
Suspicious Flight School Student
Instructors at an Arizona flight school become suspicious about a students who speaks English poorly and has limited flying skills. They report him to the FAA. The student, Hani Hanjour, a Saudi, later pilots a plane into the Pentagon on Sept. 11.
Specific Threat On U.S. Targets
Washington reportedly receives a “specific threat” that Al Qaeda may attempt to attack American targets in the Middle East or Europe.
April 18, 2001
Another FAA Warning
This warning to airlines states: “The FAA does not have any credible information regarding specific plans by terrorist groups to attack U.S. civil aviation interests… Nevertheless some of the current active groups are known to plan and train for hijackings… The FAA encourages U.S. carriers to demonstrate a high degree of alertness.”
May 11, 2001
State Dept. Warns Americans Overseas
The State Department warns that American citizens overseas may be targeted by Al Qaeda.
May 29, 2001
East Africa Convictions
Mohamed al-‘Owhali, Khalfan Khamis Mohamed, Mohammed Saddiq Odeh, and Wadih el-Hage are convicted on charges including conspiracy to kill Americans, which stem from the 1998 embassy bombings.
Visa Issued to Almidhar
The State Department re-issues a visa to Khalid Almidhar, a Sept. 11 hijacker who was present at the January 2000 Malaysia meeting.
FBI Withdraws from Yemen.More FAA Warnings
Citing a security threat, the FBI pulls investigators out of Yemen. This same month, the FAA issues more warnings to airlines. The NSC’s Richard Clarke later tells FRONTLINE that those warnings were “absolutely” related to Al Qaeda operatives discussing what would eventually become the Sept. 11 attacks.
By late June, intelligence experts are extremely concerned about the possibility of an imminent attack.
State Department Closes Embassies
The U.S. embassies in Senegal and Bahrain are shut down and the State Department issues a new worldwide caution.
Attack on Yemen Embassy Thwarted
Yemeni authorities thwart an attack on the U.S. embassy in Sana, Yemen.
June 22, 2001
U.S. Central and European Command impose “Force Protection Condition Delta” because of concerns about a terrorist attack.
June 28, 2001
Attack «Highly Likely»
National Security Adviser Condoleezza Rice is warned during an intelligence briefing that an Al Qaeda attack is “highly likely.”
FBI Investigators ID Cole Suspects at Malaysia Meeting
Sources close to the Cole investigation tell FRONTLINE that during the summer of 2001 the CIA informs the FBI about the Malaysia meeting and shows them a picture of one or two of the Cole suspects. The FBI reportedly identifies Cole suspects Tawfiq bin-Atash and Fahad al-Quso. Al-Quso would later deny that he made it to the meeting and claims that the individual in the picture just looked like him.
July 4, 2001
Almidhar Re-enters U.S.
Khalid Almidhar re-enters the U.S. through JFK airport. He later meets with Mohamed Atta.
July 10, 2001
Mohamed Atta meets with his former roommate Ramzi bin al-Shibh in Spain along with a number of other Arab men. Only after Sept. 11 do officials discover the meeting and conclude that bin al-Shibh also may have been at the January 2000 Malaysia meeting.
July 10, 2001
Request for Flight School Investigation
The FBI’s Phoenix office sends a memo to FBI headquarters requesting officials initiate a nationwide investigation of flight schools. The memo warns that bin Laden supporters may be attending flight schools in the United States.
July 18, 2001
The FBI warns that the conviction of Ahmed Ressam for the millennium plot to detonate a bomb at Los Angeles airport could lead to retaliatory terrorist attacks.
July 31, 2001
Another FAA Alert
The FAA issues yet another warning to airlines that terrorists could be planning to hijack American airlines.
Bin Laden Operatives Return to Afghanistan
According to a later report by the British government, “In August and early September  close associates of bin Laden were warned to return to Afghanistan from other parts of the world by Sept. 10.”
Aug. 16, 2001
FAA Warns of Weapons from Everyday Objects
The FAA warns airlines that terrorists may use weapons modified from everyday objects.
Aug. 16, 2001
Minneapolis FBI agents pick up and arrest Zacarias Moussaoui on immigration charges for overstaying his visa, but agents are concerned he could be a terrorist. The Minneapolis office tries unsuccessfully to secure either a criminal search warrant or an intelligence warrant to search Moussaoui’s belongings. After Sept. 11, a federal indictment would claim that Moussaoui was in possession of two knives, a flight manual for a 747-400, fighting gloves and shin guards, and an aviation radio.
Aug. 27, 2001
CIA Cables FBI Names of Almidhar and Alhazmi
The CIA cables the FBI, warning that Khalid Almidhar and Nawaf Alhazmi are inside the U.S. and are suspected terrorists because of their presence at the January 2000 Malaysia meeting.
Aug. 28, 2001
French Brief FBI on Moussaoui
They say Moussaoui has been linked to Al Qaeda.
Sept. 5, 2001
Bin al-Shibh Leaves for Afghanistan
Ramzi bin al-Shibh, the former roommate of Mohamed Atta, who had attended both the July meeting in Spain and the January 2000 Malaysia meeting, leaves Germany for Afghanistan.
Sept. 11, 2001
Sept. 11 Attacks
Hijackers alleged to be members of Al Qaeda take control of four airliners and crash two into the World Trade Center, and one into the Pentagon. A fourth hijacked plane crashes into the Pennsylvania countryside. The attacks kill more than 3,000 people.
Post-Sept. 11, 2001
Postscript: Links to 1995 Bojinka Plotter; al-Shibh Captured
U.S. investigators discover evidence they believe links Khalid Shaikh Mohammed — wanted and still at large for his role in the 1995 Bojinka plot — to the Sept. 11 hijackings. A few weeks later, U.S. officials say they believe that Khalid Shaikh Mohammed is the operations chief of Al Qaeda. It is also later reported that the National Security Agency had intercepted telephone conversations between Mohamed Atta and Khalid Shaikh Mohammed before Sept. 11, but had not “properly” translated them at the time. Officials quoted in one story refused to describe the content of those conversations.
On Sept. 11, 2002, Ramzi bin al-Shibh is captured by Pakistani police in a shootout in Karachi. He is currently in U.S. custody and, according to a U.S. Defense Department official, is “providing valuable information.” Bin al-Shibh is believed to have knowledge of Al Qaeda operations in Europe and Southeast Asia.
2004 Update: Khalid Shaikh Mohammed now in U.S. custody – see details.