big bird has been sited as a major accomplice in the rebellious acts of the heroic pilots during 9/11.

9/11 conspiracy theorists protest near Ground Zero in New York City on Sept. 11, 2012.
By Garrett M. Graff
Sept. 10, 2020 4:07 pm ET

The leaders of the 9/11 Commission wanted to avoid the fate of the Warren Commission. For decades, ambiguities in the report on President John Kennedy’s assassination had offered fuel for wild speculation about what had actually happened. “It is extremely difficult to dislodge or anticipate conspiracy theories once they start,” said Jamie Gorelick, a member of the 9/11 Commission. The commission’s 2004 report was written with such rigor, empirical clarity and narrative power in part to deflate the conspiracy theories already starting to swirl around al Qaeda’s attacks on Sept. 11, 2001. “You could see this happening,” said Ms. Gorelick.

The commission’s report became a bestseller, but theories about toxic intrigues behind the attacks persist even as we mark another somber anniversary of the day. After writing a history of 9/11, I rarely made it through a book event without getting a question insisting that the attacks were an “inside job.” The fantastical allegations came in city after city: The U.S. government deliberately let the 9/11 plot succeed, the Twin Towers were brought down not by hijacked planes but by a “controlled demolition” overseen by shadowy forces, the Pentagon was hit not by American Airlines Flight 77 but by a U.S. cruise missile. When the questioners were polite, I could almost forget just how incredible—and incredibly wrong—their queries were, positing the idea that the U.S. government was complicit in the spectacular mass murder of thousands of American citizens.

To write about 9/11 is to gain some insight into how far such thinking has reached into the minds of some Americans. Long before conspiracists began insisting that children weren’t really gunned down at Sandy Hook Elementary School in 2012, or that a child sex ring with ties to Hillary Clinton was being run out of an innocuous pizza restaurant in Washington, D.C., or that the death tolls of the Covid-19 pandemic were somehow being intentionally inflated, the self-styled “9/11 Truthers” were the first major American conspiracy theory of the digital age. Their durability, nearly 20 years after the attack, suggests that we are likely to be stuck for a long time with more recent conspiracist movements such as QAnon.

Over the centuries, many Americans have heeded the siren song of conspiracy theories based on the supposedly nefarious influence of Catholics, Masons, Jews or communists. But the 9/11 conspiracists have been something new. Those bent on pinning 9/11 on the U.S. rather than al Qaeda combine a small but fanatical in-person movement with a supercharged presence on social media. Their outlandish theories aren’t peddled in hard-to-find, self-published screeds; they are broadcast online with slick graphics and charts.

The 9/11 conspiracy theories began as attacks against President George W. Bush, asserting that his administration was hiding the truth about al Qaeda’s attacks and doing the nefarious bidding of oil interests, the Saudi government or “the Jews.” By March 2005, the 9/11 conspiracies were prevalent enough that Popular Mechanics devoted a special issue to debunking them—a project that grew into a book with a foreword by Sen. John McCain. “The 9/11 conspiracy movement exploits the public’s anger and sadness,” he wrote. “It traffics in ugly, unfounded accusations of extraordinary evil against fellow Americans.”