9/11 Advance Knowledge — Who Knew?

Overview

The 9/11 advance knowledge theory encompasses a range of claims that elements within the United States government, foreign intelligence services, or the financial sector had prior warning of the September 11, 2001 terrorist attacks and either failed to act on that information or deliberately allowed the attacks to proceed. Unlike the more extreme “inside job” theories that allege the US government orchestrated the attacks, the advance knowledge theory focuses on documented intelligence failures, suppressed warnings, and unexplained anomalies in the lead-up to the attacks.

This theory occupies an unusual position in the conspiracy theory landscape because several of its core elements are supported by documented evidence. The 9/11 Commission Report itself acknowledged significant intelligence failures, including the CIA’s failure to share information about known Al-Qaeda operatives entering the United States. FBI whistleblower Coleen Rowley’s testimony about headquarters blocking the Minneapolis field office’s investigation of Zacarias Moussaoui is a matter of congressional record. The existence of the August 6, 2001 Presidential Daily Briefing titled “Bin Laden Determined to Strike in US” is confirmed fact.

The theory is classified as “mixed” because it contains elements that are confirmed (intelligence agencies did receive warnings and failed to act on them), elements that remain genuinely unresolved (the full extent of Saudi government involvement, the completeness of the put options investigation), and elements that have been addressed by official investigations but continue to be disputed by credible researchers and whistleblowers.

Origins & History

The Immediate Aftermath (September-December 2001)

Questions about advance knowledge began circulating almost immediately after the attacks. Within weeks, news reports emerged about the August 6, 2001 PDB, about warnings from foreign intelligence services, and about the FBI’s failure to follow up on the Moussaoui arrest in Minnesota. Richard Clarke, the National Security Council’s counterterrorism coordinator, publicly stated that he had been warning about an imminent Al-Qaeda attack throughout the summer of 2001.

In the immediate aftermath, the Bush administration resisted calls for an independent investigation into intelligence failures. President Bush and Vice President Cheney personally lobbied congressional leaders against establishing an independent commission, arguing that it would divert resources from the ongoing war in Afghanistan.

The Joint Congressional Inquiry (2002)

The first major investigation was the Joint Inquiry into Intelligence Community Activities Before and After the Terrorist Attacks of September 11, 2001, conducted by the Senate and House intelligence committees. The inquiry produced a detailed report documenting intelligence failures, but 28 pages dealing with potential Saudi government involvement were classified at the request of the Bush administration. The classification of these pages became a focal point for advance knowledge theorists, who argued that the redaction concealed evidence of foreign government complicity.

The 9/11 Commission (2002-2004)

The National Commission on Terrorist Attacks Upon the United States, commonly known as the 9/11 Commission, was established in November 2002 after sustained pressure from victims’ families, particularly the “Jersey Girls” — four women from New Jersey whose husbands died in the attacks. The Commission’s final report, published in July 2004, documented extensive intelligence failures but concluded they resulted from systemic problems — information sharing barriers, bureaucratic competition between agencies, and a failure of imagination — rather than deliberate inaction.

However, several Commission members and staff later expressed concerns about the investigation’s completeness. Commissioner Max Cleland resigned, calling the investigation compromised. Commissioner Tim Roemer stated that the Commission was “set up to fail.” Senior counsel John Farmer wrote a book arguing that government officials had given “false” accounts to the Commission about their actions on the day of the attacks.

Post-Commission Developments (2005-Present)

The advance knowledge debate continued after the Commission’s final report:

• Able Danger revelations (2005): Lt. Col. Anthony Shaffer went public with claims that a classified military intelligence program had identified hijacker Mohamed Atta before 9/11.
• 28 pages declassification campaign (2003-2016): A bipartisan group of legislators, supported by 9/11 families, campaigned for the declassification of the redacted Joint Inquiry pages.
• 28 pages released (2016): The pages were partially declassified, revealing details about potential Saudi government connections to the hijackers.
• FBI lawsuit documents (2019-2022): Litigation by 9/11 families against Saudi Arabia produced additional documents detailing contacts between hijackers and individuals connected to the Saudi government.

Key Claims

The advance knowledge theory encompasses several distinct but interconnected claims:

Intelligence Warning Claims

• The CIA tracked two of the future hijackers (Nawaf al-Hazmi and Khalid al-Mihdhar) to a January 2000 Al-Qaeda meeting in Kuala Lumpur but did not place them on watchlists or inform the FBI until August 2001
• The August 6, 2001 PDB warned specifically that Bin Laden was planning to strike inside the United States, including possible hijackings, but the administration took no action
• The FBI’s Phoenix field office sent a memo in July 2001 warning about suspicious Middle Eastern men enrolled in US flight schools, but headquarters took no action
• FBI agent Coleen Rowley’s Minneapolis field office was blocked by headquarters from obtaining a warrant to search Zacarias Moussaoui’s computer after his arrest in August 2001
• Multiple foreign intelligence services — including those of Israel, Germany, France, Russia, Egypt, and Jordan — warned the US about an imminent Al-Qaeda attack in the summer of 2001
• NSA intercepted communications on September 10, 2001 that said “tomorrow is zero hour” and “the match begins tomorrow,” but did not translate them until September 12

Financial Anomaly Claims

• Unusual volumes of put options were purchased on American Airlines and United Airlines stock in the days before September 11
• Similar anomalous trading was observed in companies with offices in the World Trade Center, including Morgan Stanley and Merrill Lynch
• The 9/11 Commission’s investigation of these trades was insufficiently thorough and relied heavily on the SEC’s determination that the traders had no Al-Qaeda connections
• Short selling of airline and insurance company stocks spiked in the week before the attacks

Able Danger Claims

• The classified military intelligence program identified Mohamed Atta and three other hijackers as potential threats before September 11, 2001
• Program analysts were prevented from sharing this information with the FBI due to legal restrictions on military intelligence operations involving US persons
• The Defense Department destroyed Able Danger data after the program was shut down
• The 9/11 Commission was informed about Able Danger but did not include it in its final report

Saudi Connection Claims

• Two of the hijackers (al-Hazmi and al-Mihdhar) received financial and logistical support from individuals connected to the Saudi embassy and consulate upon their arrival in the United States
• Omar al-Bayoumi, who assisted the hijackers in San Diego, was assessed by the FBI as likely a Saudi intelligence agent
• The classified 28 pages of the Joint Inquiry detailed these connections but were suppressed for 14 years
• Saudi Arabia’s role was systematically downplayed by both the Joint Inquiry and the 9/11 Commission due to geopolitical considerations

Israeli Intelligence Claims

• Israeli intelligence reportedly warned the US about an impending large-scale attack in the months before 9/11
• A group of Israeli nationals (“the Israeli art students”) were detained after the attacks for visa violations; some were living in proximity to the hijackers
• Five Israeli nationals were observed filming the burning towers from a New Jersey parking lot and were later detained; they worked for a moving company with alleged intelligence connections
• Proponents claim Israeli intelligence was monitoring the hijackers but did not share actionable intelligence with the US

Evidence

Confirmed Elements

The August 6 PDB: The existence and title of the Presidential Daily Briefing — “Bin Laden Determined to Strike in US” — is confirmed. National Security Advisor Condoleezza Rice initially dismissed it as “historical” in nature during her 9/11 Commission testimony, but the declassified text reveals it contained current intelligence about ongoing attack planning, FBI investigations of suspicious activity consistent with preparations for hijackings, and surveillance of federal buildings in New York.

CIA tracking failures: The CIA’s failure to watchlist al-Hazmi and al-Mihdhar is confirmed by the 9/11 Commission, the CIA Inspector General’s report, and the Justice Department Inspector General’s report. The CIA tracked the two men to a January 2000 Al-Qaeda meeting in Malaysia, knew they had US visas, and learned that al-Hazmi had entered the United States — but did not inform the FBI or place them on watchlists for 18 months.

FBI headquarters obstruction: The FBI Inspector General confirmed that headquarters blocked the Minneapolis field office’s attempts to obtain a search warrant for Moussaoui’s belongings. Agent Coleen Rowley’s detailed letter to FBI Director Robert Mueller documented the obstruction and was entered into the congressional record.

Phoenix Memo: The existence of the July 2001 memo from FBI agent Kenneth Williams recommending that the FBI investigate Middle Eastern men enrolled in US flight schools is confirmed. Headquarters took no action.

Foreign warnings: Multiple foreign intelligence services have confirmed that they warned the United States about an impending Al-Qaeda attack in the summer of 2001. Israeli, German, French, Jordanian, Egyptian, and Russian intelligence services have all acknowledged providing warnings.

NSA intercepts: The NSA confirmed that it intercepted the “tomorrow is zero hour” communications on September 10 but did not translate them until after the attacks.

Contested Elements

Put options: The SEC and 9/11 Commission investigated the unusual trading and traced a significant portion to a single US-based investment newsletter’s bearish recommendation. However, some researchers, including economist Allen Poteshman of the University of Illinois, have published peer-reviewed analysis suggesting the trading volumes were statistically anomalous even after accounting for the identified trades. The question of whether all anomalous trades were fully investigated remains contested.

Able Danger: Lt. Col. Shaffer’s claims are supported by testimony from at least four other military intelligence officers who corroborated that the program identified Atta. However, the 9/11 Commission stated it found no documentary evidence supporting the claims, and the Defense Department stated that relevant data had been destroyed in accordance with data retention policies. The destruction of the data makes independent verification impossible.

Saudi government involvement: The declassified 28 pages and subsequent FBI documents revealed significant contacts between the hijackers and individuals connected to the Saudi government. However, the nature of these contacts — whether they represented institutional Saudi support or the actions of individual officials — remains disputed. The 9/11 Commission found “no evidence that the Saudi government as an institution or senior Saudi officials individually funded” Al-Qaeda, but this finding has been challenged by researchers and 9/11 families’ attorneys who have reviewed additional documents.

Israeli intelligence monitoring: The “Israeli art students” and “dancing Israelis” incidents are documented in law enforcement reports. However, the significance of these incidents — whether they indicate Israeli foreknowledge, routine intelligence operations, or coincidence — is contested. The detained individuals were deported for immigration violations, and no charges related to the 9/11 attacks were filed.

Debunking / Verification

This theory is classified as mixed because it contains confirmed, unresolved, and debunked elements:

Confirmed: US intelligence agencies received multiple, specific warnings about an impending Al-Qaeda attack and failed to act on them. Information sharing between agencies was catastrophically inadequate. The August 6 PDB, the CIA tracking failure, the FBI headquarters obstruction, and the Phoenix Memo are all documented facts.

Unresolved: The full extent of Saudi government involvement has not been conclusively established. The Able Danger claims cannot be verified because relevant data was destroyed. Whether the put options investigation was sufficiently thorough remains debated by financial researchers. The nature and scope of Israeli intelligence activity related to the hijackers is not fully explained.

Addressed by official investigations but disputed: The 9/11 Commission concluded that the failures were systemic rather than deliberate. However, the Commission’s own members have raised concerns about the investigation’s completeness, and new documents continue to emerge through litigation.

The distinction between the advance knowledge theory and the “inside job” theory is important. Evidence of intelligence failures and even potential deliberate inaction is not evidence that the US government planned or executed the attacks. The question of whether the failures constituted incompetence, institutional dysfunction, or something more remains genuinely open.

Cultural Impact

Intelligence Reform

The documented intelligence failures that form the core of the advance knowledge theory had direct policy consequences. The Intelligence Reform and Terrorism Prevention Act of 2004 created the Office of the Director of National Intelligence to improve information sharing between agencies. The act was a direct response to the failures documented by the 9/11 Commission, including many of the same failures cited by advance knowledge theorists.

Whistleblower Recognition

Several individuals who raised advance knowledge concerns were recognized for their actions. FBI agent Coleen Rowley was named Time magazine’s Person of the Year in 2002 (jointly with two other whistleblowers). Richard Clarke’s public testimony about warning the administration was a watershed moment in 9/11 accountability.

The “LIHOP” Framework

The advance knowledge theory gave rise to the acronym LIHOP — “Let It Happen On Purpose” — which became a major framework in 9/11 conspiracy discourse. LIHOP adherents argue that elements within the government knew about the attacks and deliberately allowed them to proceed because the resulting crisis would justify desired policy outcomes (the invasion of Afghanistan and Iraq, expanded surveillance powers, increased military spending). This position occupies a middle ground between the official account (catastrophic intelligence failures) and the “MIHOP” (Made It Happen On Purpose) position that the government actively orchestrated the attacks.

Saudi Accountability Movement

The advance knowledge theory, particularly the Saudi connection element, has fueled a sustained legal and political campaign by 9/11 families. The Justice Against Sponsors of Terrorism Act (JASTA), passed in 2016 over President Obama’s veto, allowed 9/11 families to sue Saudi Arabia in US courts. The resulting litigation has produced significant new documentary evidence about Saudi connections to the hijackers.

In Popular Culture

• Fahrenheit 9/11 (2004) — Michael Moore’s documentary focused extensively on Bush administration connections to Saudi Arabia and advance knowledge questions
• The Looming Tower (2018) — Hulu miniseries based on Lawrence Wright’s Pulitzer Prize-winning book, dramatizing the CIA-FBI rivalry that contributed to intelligence failures before 9/11
• Richard Clarke, Against All Enemies (2004) — Memoir by the former counterterrorism coordinator detailing his warnings about Al-Qaeda in the months before the attacks
• Lawrence Wright, The Looming Tower (2006) — Pulitzer Prize-winning account of the road to 9/11, documenting intelligence failures and bureaucratic competition
• John Farmer, The Ground Truth (2009) — Book by the 9/11 Commission’s senior counsel arguing that government officials gave false accounts of their actions on September 11

Key Figures

• Richard Clarke — NSC counterterrorism coordinator who publicly testified that he warned the Bush administration about Al-Qaeda throughout the summer of 2001
• Coleen Rowley — FBI agent who documented headquarters’ obstruction of the Moussaoui investigation; named Time Person of the Year 2002
• George Tenet — CIA Director who later stated the intelligence community’s hair was “on fire” about an impending attack in the summer of 2001
• Condoleezza Rice — National Security Advisor who received the August 6 PDB and initially characterized it as “historical”
• Lt. Col. Anthony Shaffer — Military intelligence officer who claimed the Able Danger program identified hijacker Mohamed Atta before 9/11
• Kenneth Williams — FBI Phoenix field office agent who authored the July 2001 memo about suspicious flight school enrollments
• Max Cleland — 9/11 Commission member who resigned, calling the investigation compromised
• Bob Graham — Senate Intelligence Committee chair who co-led the Joint Inquiry and campaigned for declassification of the 28 pages

Timeline

• January 2000 — CIA tracks al-Hazmi and al-Mihdhar to Al-Qaeda meeting in Malaysia; does not inform FBI
• January 15, 2000 — Al-Hazmi and al-Mihdhar enter the United States; CIA does not watchlist them
• July 10, 2001 — CIA Director Tenet briefs Rice on urgent Al-Qaeda threat intelligence
• July 10, 2001 — FBI Phoenix Memo warns about Middle Eastern men in flight schools
• August 6, 2001 — President Bush receives PDB titled “Bin Laden Determined to Strike in US”
• August 16, 2001 — Zacarias Moussaoui arrested in Minnesota; FBI headquarters blocks warrant request
• August 23, 2001 — CIA finally places al-Hazmi and al-Mihdhar on watchlists — 19 days before the attacks
• September 10, 2001 — NSA intercepts “tomorrow is zero hour” communication; not translated until September 12
• September 11, 2001 — Terrorist attacks on World Trade Center, Pentagon, and Flight 93
• November 2002 — 9/11 Commission established after sustained pressure from victims’ families
• July 2003 — Joint Inquiry report released with 28 pages classified
• July 2004 — 9/11 Commission Report published
• August 2005 — Lt. Col. Shaffer goes public with Able Danger claims
• July 2016 — 28 pages partially declassified
• September 2016 — JASTA passes, allowing lawsuits against Saudi Arabia
• 2019-present — FBI documents about Saudi connections released through litigation

Sources & Further Reading

• National Commission on Terrorist Attacks Upon the United States. The 9/11 Commission Report. W.W. Norton, 2004.
• Wright, Lawrence. The Looming Tower: Al-Qaeda and the Road to 9/11. Alfred A. Knopf, 2006.
• Clarke, Richard. Against All Enemies: Inside America’s War on Terror. Free Press, 2004.
• Farmer, John. The Ground Truth: The Untold Story of America Under Attack on 9/11. Riverhead Books, 2009.
• Rowley, Coleen. Letter to FBI Director Robert Mueller. May 21, 2002. Congressional Record.
• Poteshman, Allen M. “Unusual Option Market Activity and the Terrorist Attacks of September 11, 2001.” Journal of Business 79, no. 4 (2006): 1703-1726.
• Graham, Bob. Intelligence Matters: The CIA, the FBI, Saudi Arabia, and the Failure of America’s War on Terror. Random House, 2004.
• Shenon, Philip. The Commission: The Uncensored History of the 9/11 Investigation. Twelve Books, 2008.
• Joint Inquiry into Intelligence Community Activities Before and After the Terrorist Attacks of September 11, 2001. Final Report, including declassified “28 pages.” December 2002 / July 2016.

Related Theories

• 9/11 Inside Job — The broader theory that the US government orchestrated the September 11 attacks
• 9/11 Controlled Demolition — Claims that the World Trade Center towers were brought down by pre-planted explosives
• Saudi 9/11 Connection — The specific focus on Saudi government involvement in the attacks
• Building 7 Demolition — Questions about the collapse of World Trade Center 7
• Pentagon Missile Theory — The claim that the Pentagon was struck by a missile rather than Flight 77