There are many conspiracy theories that attribute the planning and execution of the September 11 attacks against the United States to parties other than, or in addition to, al-Qaeda including that there was advance knowledge of the attacks among high-level government officials. Government investigations and independent reviews have rejected these theories. Proponents of these theories assert that there are inconsistencies in the commonly accepted version, or evidence that was either ignored or overlooked.
The most prominent conspiracy theory is that the collapse of the Twin Towers and 7 World Trade Center were the result of controlled demolitions rather than structural failure due to impact and fire. Another prominent belief is that the Pentagon was hit by a missile launched by elements from inside the U.S. government or that a commercial airliner was allowed to do so via an effective stand-down of the American military. Possible motives claimed by conspiracy theorists for such actions include justifying the invasions of Afghanistan and Iraq (even though the U.S. government concluded Iraq was not involved in the attacks) to advance their geostrategic interests, such as plans to construct a natural gas pipeline through Afghanistan. Other conspiracy theories revolve around authorities having advance knowledge of the attacks and deliberately ignoring or assisting the attackers.
The National Institute of Standards and Technology (NIST) and the technology magazine Popular Mechanics have investigated and rejected the claims made by 9/11 conspiracy theorists. The 9/11 Commission and most of the civil engineering community accept that the impacts of jet aircraft at high speeds in combination with subsequent fires, not controlled demolition, led to the collapse of the Twin Towers, but some groups disagree with the arguments made by NIST and Popular Mechanics, including Architects & Engineers for 9/11 Truth.
9/11 conspiracy theorists reject one or both of the following facts about the 9/11 attacks:
Al-Qaeda suicide operatives hijacked and crashed United Airlines Flight 175 and American Airlines Flight 11 into the twin towers of the World Trade Center, and crashed American Airlines Flight 77 into the Pentagon. The impact and resulting fires caused the collapse of the Twin Towers and the destruction and damage of other buildings in the World Trade Center complex. The Pentagon was severely damaged by the impact of the airliner and the resulting fire. The hijackers also crashed a fourth plane into a field near Shanksville, Pennsylvania after the passengers and flight crew attempted to regain control of the aircraft.
Pre-attack warnings of varying detail of the planned attacks against the United States by al-Qaeda were ignored due to a lack of communication between various law enforcement and intelligence personnel. For the lack of interagency communication, the 9/11 report cited bureaucratic inertia and laws passed in the 1970s to prevent abuses that caused scandals during that era, most notably the Watergate scandal. The report faulted both the Clinton and the Bush administrations with “failure of imagination.”
This consensus view is backed by various sources, including:
- The reports from government investigations – the 9/11 Commission Report (that incorporated intelligence information from the earlier FBI investigation (PENTTBOM) and the Joint Inquiry of 2002), and the studies into building performance carried out by the Federal Emergency Management Agency (FEMA) and the National Institute of Standards and Technology (NIST)
- Investigations by non-government organizations that support the accepted account – such as those by scientists at Purdue University.
- Articles supporting these facts and theories appearing in magazines such as Popular Mechanics, Scientific American, and Time.
- Similar articles in news media throughout the World, including The Times of India, the Canadian Broadcasting Corporation (CBC), the BBC, Le Monde, Deutsche Welle, the Australian Broadcasting Corporation (ABC), and The Chosun Ilbo of South Korea.
Since the attacks, a variety of conspiracy theories have been put forward in Web sites, books, and films. Many groups and individuals advocating 9/11 conspiracy theories identify as part of the 9/11 Truth movement.
Within six hours of the attack, a suggestion appeared on an Internet chat room suggesting that the collapse of the towers looked like an act of controlled demolition. “If, in a few days, not one official has mentioned anything about the controlled demolition part,” the author wrote, “I think we have a REALLY serious problem.” The first theories that emerged focused primarily on various perceived anomalies in the publicly available evidence, and proponents later developed more specific theories about an alleged plot. One false allegation that was widely circulated by e-mail and on the Web is that not a single Jew had been killed in the attack and that therefore the attacks must have been the work of the Mossad, not Islamic terrorists. Similar e-mail narratives claimed that all Arab taxi drivers were absent in downtown Manhattan that morning.
The first elaborated theories appeared in Europe. One week after the attacks, the “inside job” theory was the subject of a thesis by a researcher from the French National Centre for Scientific Research published in Le Monde. Other theories sprang from the far corners of the globe within weeks. Six months after the attacks, Thierry Meyssan’s piece on 9/11, L’Effroyable Imposture, topped the French bestseller list. Its publication in English (as 9/11: The Big Lie) received little attention, but it remains one of the principal sources for “trutherism”. 2003 saw the publication of The CIA and September 11 by former German state minister Andreas von Bülow and Operation 9/11 by the German journalist Gerhard Wisnewski; both books are published by Mathias Bröckers, who was at the time an editor at the German newspaper Die Tageszeitung.
While these theories were popular in Europe, they were treated by the U.S. media with either bafflement or amusement, and they were dismissed by the U.S. government as the product of anti-Americanism. In an address to the United Nations on November 10, 2001, President George W. Bush denounced the emergence of “outrageous conspiracy theories […] that attempt to shift the blame away from the terrorists, themselves, away from the guilty.”
The 9/11 conspiracy theories started out mostly in the political left but have broadened into what New York magazine describes as “terra incognita where left and right meet, fusing sixties countercultural distrust with the don’t-tread-on-me variety”.
By 2004, conspiracy theories about the September 11 attacks began to gain ground in the United States. One explanation is that the rise in popularity stemmed more from growing criticism of the Iraq War and the newly re-elected President George W. Bush than from any discovery of new or more compelling evidence or an improvement in the technical quality of the presentation of the theories. Knight Ridder news theorized that revelations that weapons of mass destruction did not exist in Iraq, the belated release of the President’s Daily Brief of August 6, 2001, and reports that NORAD had lied to the 9/11 Commission, may have fueled the conspiracy theories.
Between 2004 and the fifth anniversary of the September 11 attacks in 2006, mainstream coverage of the conspiracy theories increased. The U.S. government issued a formal analysis by the National Institute of Standards and Technology (NIST) of the collapse of the World Trade Center. To address the growing publicity of the theories, the State Department revised a webpage in 2006 to debunk them. A 2006 national security strategy paper declared that terrorism springs from “subcultures of conspiracy and misinformation,” and that “terrorists recruit more effectively from populations whose information about the world is contaminated by falsehoods and corrupted by conspiracy theories. The distortions keep alive grievances and filter out facts that would challenge popular prejudices and self-serving propaganda.” Al-Qaeda has repeatedly claimed responsibility for the attacks, with chief deputy Ayman al-Zawahiri accusing Shia Iran and Hezbollah of denigrating Sunni successes in hurting America by intentionally starting rumors that Israel carried out the attacks.
Some of the conspiracy theories about the September 11 attacks do not involve representational strategies typical of many conspiracy theories that establish a clear dichotomy between good and evil, or guilty and innocent; instead, they call up gradations of negligence and complicity. Matthias Bröckers, an early proponent of such theories, dismisses the commonly accepted account of the September 11 attacks as being itself a conspiracy theory that seeks “to reduce complexity, disentangle what is confusing,” and “explain the inexplicable”.
Just before the fifth anniversary of the attacks, mainstream news outlets released a flurry of articles on the growth of 9/11 conspiracy theories, with an article in Time stating that “[t]his is not a fringe phenomenon. It is a mainstream political reality.” Several surveys have included questions about beliefs related to the September 11 attacks. In 2008, 9/11 conspiracy theories topped a “greatest conspiracy theory” list compiled by The Daily Telegraph. The list was ranked by following and traction.
In 2010, the “International Center for 9/11 Studies,” a private organization that is said to be sympathetic to conspiracy theories, successfully sued for the release of videos collected by NIST of the attacks and aftermath. According to the German daily Frankfurter Allgemeine Zeitung, the videos that were published shortly before the ninth anniversary of the attacks provide “new food for conspiracy theorists.” Many of the videos show images of 7 World Trade Center, a skyscraper in the vicinity of the WTC towers that also collapsed on September 11, 2001. Eyewitnesses have repeatedly reported explosions happening before the collapse of both of the towers, while experts consider these theories to be unreasonable.
9/11 truth figures Steven E. Jones and Mike Berger have further added that the death of Osama bin Laden did not change their questions about the attacks, nor provide closure.
According to writer Jeremy Stahl, since Bush left office, the overall number of believers in 9/11 conspiracy theories has dipped, while the number of people who believe in the most “radical” theories has held fairly steady.