September 11 Advance-Knowledge Conspiracy Theories

Advance-knowledge theories often collapse three different questions: whether intelligence agencies received broad strategic warnings, whether officials missed investigative opportunities, and whether a person or government possessed specific operational knowledge of the attacks' date, targets, and method. Official records document the first two but do not establish the third. The Congressional Research Service reported that the intelligence community had ample warning of an impending al-Qaeda attack but did not learn the aircraft-hijacking plan in advance, while the Justice Department Inspector General found no evidence that the FBI or another intelligence agency had specific intelligence about the September 11 plot.[1][2]

The principal variants allege foreknowledge or participation by the U.S. government, Israel or the Mossad, Jewish employees or investors, and people associated with the hijackers. Their recurring purported evidence includes the false "4,000 Jews" rumor, allegations involving detained Israeli nationals, unusual airline-stock trading, general pre-attack threat reporting, and missed opportunities involving future hijackers.[3][4]

Rumors attributing the September 11 attacks to Israeli, Jewish, or American government actors began circulating within hours of the strikes on the World Trade Center, the Pentagon, and a Pennsylvania field.[5] A key early vector was Al-Manar, the Lebanese television station operated by Hezbollah, which on September 17, 2001, broadcast the claim that 4,000 Israelis or Jews had been warned to stay away from the World Trade Center on the morning of the attacks.[6] The U.S. State Department later identified that broadcast as the first known appearance of the "4,000 Jews" claim.[6]

From Al-Manar, the story spread rapidly through newspapers and Internet platforms from Saudi Arabia to Pakistan before being adopted by white supremacist and far-right groups in the United States.[4] Outlets that amplified the claim included The David Duke Report, The Aryan Eagle, David Irving's Action Report, Islamweb, the Tehran Times, and the Islamic Republic News Agency.[4] David Duke misrepresented a September 12, 2001, Jerusalem Post article as reporting that 4,000 Israelis were missing from the World Trade Center and that only one Israeli had died. The article actually described approximately 4,000 names supplied by worried Israelis who could not reach relatives and friends in the affected areas, many of whom were subsequently located.[4] The Israeli Consulate later confirmed that seven Israeli citizens died in the attacks.[4]

As the claim that 4,000 Israelis had worked at the World Trade Center became implausible, some promoters adapted the allegation to assert instead that American Jews broadly had been warned not to report for work.[4] The conspiracy narrative entered political and diplomatic discourse quickly: the Syrian ambassador to Iran stated at an Iranian Foreign Ministry conference on October 24, 2001, that the alleged absence of 4,000 Jews demonstrated Zionist involvement in the attacks.[6] A June 2002 cartoon in Qatar's Al-Watan depicted Ariel Sharon watching an Israeli plane crash into the World Trade Center.[6] A Washington Post survey found that 71 percent of questioned Pakistanis considered the 4,000-Jewish-survivors story a possible fact, while only 16 percent called it baseless.[6]

In the United States, Holocaust deniers circulated paid advertisements and opinion pieces developing themes of Jewish or Israeli culpability in more than 25 campus newspapers during the fall 2001 semester. At least one campus newspaper published the claim that the attacks had been carried out by the Mossad and that Jewish employees had been warned in advance.[7]

The allegation that 4,000 Israeli or Jewish employees were warned to stay home from the World Trade Center became the most widely circulated conspiracy theory concerning Jewish or Israeli involvement in the attacks.[4] It was identified as one of the most persistent antisemitic 9/11 myths.[4]

The figure originated in a Jerusalem Post report from September 12, 2001, stating that approximately 4,000 Israelis were believed to have been in the areas of the World Trade Center and the Pentagon—meaning the New York City and Washington, D.C., metropolitan areas—and that concerned relatives and friends had submitted their names to Israeli authorities.[6][4] That figure was transformed in conspiracy discourse into a claim that 4,000 Israelis or Jews had specifically stayed away from work inside the Twin Towers on the morning of the attacks.

There was no mass absence of any identifiable group at the World Trade Center on September 11.[6] An estimated 10 to 15 percent of the 2,071 World Trade Center occupants who died were Jewish, a proportion evidenced by the funerals held for victims at synagogues and temples.[6]

A related variant alleged that Ariel Sharon canceled a planned New York trip because he knew what would happen on September 11. In fact, Sharon's visit had been scheduled for September 23, 2001, to participate in a pro-Israel rally organized by Jewish organizations, and it was canceled after the attacks occurred—not before them.[4]

A second major cluster of theories alleged that Israel had operationally penetrated or monitored the September 11 hijacking plot through clandestine intelligence activities in the United States. Two distinct groups—a larger cohort of young Israelis described as art students and five Israeli men detained near the World Trade Center—became focal points for these claims.

More than 100 Israeli nationals were detained or arrested before and after September 11 in connection with allegations that they had posed as art students, tracked the hijackers, and possessed advance knowledge of the planned attacks while failing to warn U.S. authorities.[4] The FBI, the Department of Justice, and Israeli authorities denied that such an Israeli spy ring existed, although they acknowledged visa violations and deportations involving some of the young Israelis.[4] The Washington Post described the spy-ring story as an "urban myth," and no investigator involved in the case connected the detained Israelis to the September 11 plot.[4]

The five Israeli nationals—later known in conspiracy literature as the "dancing Israelis"—were detained after witnesses reported seeing them apparently celebrating or filming while the World Trade Center burned.[4] An FBI investigation opened on September 14, 2001, and closed on July 10, 2003, examined those allegations in detail.[8] The FBI found that the men had taken still photographs with a 35mm camera but found no factual or substantive circumstantial information corroborating claims that they had filmed the attacks before the first impact.[8] The photographs did not show the towers before the attack, and numerous facts supported the men's account that they learned of the attacks from radio broadcasts and Internet news before going to observe.[8]

FAA radar and news-helicopter data placed the men at their Union City, New Jersey, observation point sometime between approximately 8:50 and 9:03 a.m., consistent with their being there after the first World Trade Center impact and before the second.[9] No video camera was found during a search of Urban Moving Systems, and no pre-impact images appeared on the developed film.[9] The FBI documents record circumstances that fueled later conspiracy claims, including witness reports of smiling, hugging, and giving "high fives" near a white van, discrepancies in accounts of the men's movements, the absence of normal moving-company equipment, and a reported positive indication by a bomb-sniffing dog.[9]

Laboratory results establishing actual explosive traces were not provided in the relevant summary. The circumstances did not overcome the FBI's conclusion that the men most likely lacked prior knowledge of the attacks and were not conducting clandestine intelligence activities in the United States.[9]

The men had worked illegally for Urban Moving Systems and violated their tourist visas; they were imprisoned for more than two months before being deported to Israel.[4] The U.S. and Israeli governments denied they were intelligence operatives.[4] An ABC 20/20 report argued that they were probably spies while explicitly acknowledging that there was "no evidence to conclude they had advanced knowledge of the terrorist attacks of 9/11."[4]

Additional foreknowledge claims focused on two Israeli-connected companies. Conspiracy writers cited Zim Israel's move from its World Trade Center offices approximately two weeks before the attacks as evidence of advance knowledge and pointed to messages received by employees at Odigo's Israel office on September 11 warning of an impending attack.[4] The Odigo messages were vague, did not mention the World Trade Center or Pentagon, came from an unknown sender, and were passed to Israeli authorities and the FBI. The FBI investigated them, but their origin was not explained.[4]

Theories alleging that people with advance knowledge profited through securities trading attracted substantial investigative attention. The 9/11 Commission reported that the Securities and Exchange Commission, the FBI, other U.S. agencies, foreign governments, and the securities industry conducted exhaustive investigations and found no evidence that anyone with advance knowledge had profited through securities transactions.[3][10]

The trading claims centered on unusual put-option activity in United Airlines stock on September 6, 2001, and American Airlines stock on September 10, 2001. The activity initially appeared suspicious because put options increase in value when a stock price falls.[3] Investigators found that a single U.S.-based institutional investor with no connection to al-Qaeda bought 95 percent of the United Airlines put options at issue. They traced the American Airlines activity to recommendations circulated by an options-trading newsletter.[3][10]

A separate antisemitic variant alleged that Jewish shareholders sold airline and insurance stocks approximately ten days before the attacks, repurchased them at their lowest post-attack prices, and thereby profited from the destruction.[11] Larry Silverstein's July 2001 signing of a 99-year lease on the World Trade Center complex, his partnership with Westfield America, and the involvement of Frank Lowy and Lewis Eisenberg were recast as evidence that Jewish businessmen had arranged the buildings' destruction to collect insurance proceeds.[4] These claims converted ordinary commercial property transactions and insurance coverage into supposed proof of a coordinated plot, reflecting stereotypes of Jewish greed rather than evidence of wrongdoing.[4]

Beyond the incidents involving the detained Israelis and the "4,000" claim, broader versions of the theories alleged that the Mossad or Israel had planned and executed the attacks, infiltrated al-Qaeda, manipulated the Muslim hijackers, or deliberately arranged for blame to fall on al-Qaeda and the Taliban.[4] Proposed motives included provoking U.S. military action against Afghanistan and Arab or Muslim countries, diverting attention from Israeli policies toward Palestinians, weakening Arab-Muslim unity, and advancing Israeli geopolitical interests.[4] These claims draw on antisemitic themes portraying Jews as uniquely capable of manipulating governments, media, finance, wars, and world events.[4]

Former Mossad chief Efraim Halevy directly rejected the claim that Israeli intelligence had specific prior knowledge of the attacks, stating: "There was no prior warning of the event in the United States. It caught everyone by surprise."[12] General intelligence cooperation and reports of a possible major al-Qaeda assault existed, but Halevy said there had been no specific knowledge of the date, targets, or method of September 11.[12]

Reports in Arab, Iranian, European, and American outlets circulated allegations that Israeli spies had prior knowledge, that Israelis warned Jewish communities but not U.S. authorities, that the United States or Israel planned the attacks to justify wars, that aircraft were remotely controlled, and that the buildings were destroyed with explosives rather than by the aircraft impacts.[4] These were allegations promoted by conspiracy theorists, not established facts.[4]

Belief in 9/11 revisionism persisted in parts of the Arab world, with some Egyptian political figures attributing the attacks to U.S. business or imperial interests, Israel, the Zionist lobby, or alleged American support for al-Qaeda.[13] A Pew survey cited in that report found that fewer than 30 percent of respondents in each of eight Muslim-majority countries said they believed groups of Arabs carried out the attacks; Egypt registered the highest reported disbelief, at 75 percent.[13]

Jewish communal and scholarly organizations have situated the advance-knowledge conspiracy theories within the long history of antisemitic scapegoating. The American Jewish Committee characterized claims that Jews, Israelis, or Zionists orchestrated or anticipated the attacks as antisemitic conspiracy theories connected to older tropes associated with the fraudulent Protocols of the Elders of Zion, including the idea of a Jewish plot to control the world and the practice of blaming Jews for unrelated catastrophes.[5] My Jewish Learning similarly described the theories as a revival of the stereotype of Jewish greed, noting that claims about Larry Silverstein's insurance settlement and alleged stock trades used familiar tropes of Jewish financial manipulation.[11]

The ADL's 2001 audit of antisemitic incidents described post-attack conspiracy theories that primarily emanated from the Arab and Islamic world and circulated widely on the Internet and in some American Arab newspapers as having no basis in reality.[7] A post-September 11 ADL poll found that 63 percent of American respondents believed the attacks occurred because terrorists disliked American values or the American way of life, rather than because of the U.S. relationship with Israel. Twenty-two percent said the attacks would not have occurred if the United States had not been such a close ally of Israel.[7]

Academic literature has documented how the theories traveled across political and cultural contexts. Efraim Sicher described claims that Muslims were supposedly not sophisticated enough to carry out the attacks and that only Israelis could have done so, characterizing the allegation as an expression of a mythical Zionist conspiracy.[14] The All-Party Parliamentary Inquiry into Antisemitism in the United Kingdom received testimony that shortly after the attacks, professionals in Yorkshire claimed that no Jew had reported for work in the Twin Towers and that the Mossad had faked the attack to cast Muslims in a negative light. It also received material from mainstream Arab television broadcasts endorsing conspiratorial links among Jews, the media, Zionism, U.S. foreign policy, and the September 11 attacks.[15]

Paul Iganski and Abe Sweiry noted that conspiracy theories alleging Jewish or Zionist responsibility for the attacks or advance knowledge of them, including the claim that thousands of Jews were secretly warned not to go to work, spread to subsequent international terrorist incidents.[16] A 2023 study by the Decoding Antisemitism research team identified the "dancing Israelis" narrative as a recurring 9/11-related myth in online commentary and placed it within a broader category of conspiracy theories insinuating Jewish power and prior knowledge.[17] The Institute for Strategic Dialogue reported that allegations that Jews or Israelis orchestrated the attacks continue to produce spikes in online antisemitic discussion around the anniversary of September 11.[18]

The Jewish Council for Public Affairs placed the conspiracy theories within broader post-September 11 rhetoric spread by media outlets, teachers, religious leaders, political figures, and Internet forums in parts of the Arab world. It identified related claims that "Zionists" controlled U.S. air traffic control and assisted the hijackings and that Jews sold airline shares before the attacks, presenting them as expressions of antisemitic and racist reaction rather than established evidence.[19]

The 9/11 Commission documented that intelligence reporting on terrorist threats reached its highest level since the millennium alert in the spring of 2001 and that by June and July, warnings indicated a high probability of near-term spectacular attacks with numerous casualties.[3] Most reports lacked specific information about the time, place, method, or target, however, and the Commission concluded: "We cannot say for certain whether these reports, as dramatic as they were, related to the 9/11 attacks."[3]

The August 6, 2001, Presidential Daily Brief, titled "Bin Ladin Determined To Strike in US," stated that bin Laden wanted to conduct terrorist attacks in the United States, that al-Qaeda maintained a support structure in the country, and that suspicious activity was consistent with preparations for hijackings or other types of attacks.[3] The Commission reported that the President regarded the document as historical in character, that no National Security Council meeting was convened to discuss a possible domestic attack as a result of it, and that the threats fell into a gap between agencies focused on foreign threats and those watching for domestic sleeper cells.[3]

The Congressional Research Service similarly distinguished between ample strategic warning of an impending attack by bin Laden's organization and specific advance knowledge of the aircraft-hijacking plan.[1] A briefing prepared for senior officials in early July 2001 stated that bin Laden would launch a significant attack against U.S. or Israeli interests in the coming weeks, designed to inflict mass casualties, with preparations complete and little or no advance warning expected. It identified no specific targets, dates, or methods.[1]

The Commission identified missed operational opportunities, including failures to watchlist Khalid al-Mihdhar and Nawaf al-Hazmi, notify the FBI about their U.S. visas and travel, recognize the significance of their presence in the United States, investigate Zacarias Moussaoui's connections, and connect these individuals to broader reports of imminent al-Qaeda activity.[3] It stated that greater resources and a different approach might have enabled investigators to find Mihdhar and Hazmi, although success would still have required luck as well as skill.[3]

The Justice Department Inspector General separately concluded that the July 10, 2001, memorandum by FBI agent Kenneth Williams was marked routine rather than urgent, presented an investigative theory rather than a specific threat, and did not reveal the September 11 attacks or their perpetrators. The Inspector General could not say that better handling would have uncovered the plot.[20] Its review of the FBI's handling of al-Mihdhar and al-Hazmi stated: "We found no evidence indicating the FBI or any other member of the Intelligence Community had specific intelligence regarding the September 11 plot."[2]

The FBI's post-9/11 PENTTBOM investigation involved more than 500,000 leads, more than 167,000 interviews, and millions of pages of documents.[21] A later FBI Review Commission found no new information that altered the 9/11 Commission's findings about the individuals responsible for the attacks or those who supported them, and no additional participants in the planning or execution of the attacks in the evidence examined for trial preparation.[21]

The 9/11 Commission found no evidence that Iran or Hezbollah knew about the planning of the attacks and no evidence that Iraq cooperated with al-Qaeda in developing or carrying out attacks against the United States.[3] It reported strong evidence that Iran facilitated the transit of some al-Qaeda members before September 11 and circumstantial evidence that Hezbollah operatives may have tracked some future hijackers, but said that the evidence could also reflect coincidence and required further investigation.[3]

The FBI Review Commission also examined allegations involving San Diego associates of hijackers al-Hazmi and al-Mihdhar. It found no evidence that Omar al-Bayoumi had advance knowledge of the attacks or knew the men were al-Qaeda operatives.[21] An allegation that Mohdar Abdullah had told fellow inmates he knew the hijackers' plans in advance could not be verified; Abdullah later denied having advance knowledge, and the review found no new information sufficient to change the original findings.[21] The FBI characterized a widely publicized allegation about a Saudi family near Sarasota, Florida, who supposedly had ties to the hijackers and left shortly before the attacks as based on a "poorly written and wholly unsubstantiated" report. It found no evidence connecting the family to the hijackers or the plot.[21]