September 11 attacks

The North Tower of the World Trade Center burning as a second plane approaches the South Tower

The September 11 attacks, often shortened to 9/11, were a series of suicide attacks carried out by al-Qaeda against civilian and government targets in the United States on September 11, 2001. The attackers hijacked four commercial planes, flying the first two into the World Trade Center in New York City and another into the Pentagon in Arlington, Virginia, while the last plane (which was intended to hit the White House) crashed into a field in Pennsylvania due to a passenger revolt. The attacks caused a total of 2,996 deaths including the 19 hijackers. Following the attacks, the U.S. Congress severely limited civil liberties and launched an NSA campaign of mass surveillance through the PATRIOT Act. The U.S. military began invasions of Iraq and Afghanistan even though most of the 9/11 hijackers were from Saudi Arabia, and on May 2, 2011, Osama bin Laden (founder and General Emir of al-Qaeda) himself was discovered and killed in Abbottabad, Pakistan.

Background

During Operation Cyclone, the USA funded Islamic extremists in Afghanistan to fight against the Soviet Union and PDPA. These mujahideen groups later became al-Qaeda, which the USA backed against Yugoslavia and the Libyan Arab Jamahiriya.

U.S. government involvement

Hijackers Nawaf al-Hazmi and Khalid al-Mihdhar, both CIA recruits

In April 2023, a released court document (a declaration by an Office for Military Commissions investigator into 9/11) revealed that two of the hijackers were CIA recruits in training who had lived in California with the FBI informant Abdussattar Shaikh in the summer of 2000. While direct involvement from the CIA during the attack is difficult to establish, the document does note the CIA had lost track of their recruits in the US after giving them a visa allowing multiple entries, shortly after which the attacks happened. The CIA also prevented the FBI from investigating these two recruits and charging them.