Suicide attack
The September 11, 2001 attacks, orchestrated by al-Qaeda, has been called "the worst attack on American soil since the Japanese attack on Pearl Harbor which thrust the United States into World War II". They involved the hijacking of four large passenger jet airliners because their long transcontinental flight plans meant they carried more fuel, allowing a bigger explosion on impact (unlike earlier airline hijackings, the primary focus was the planes, not the passengers). Two planes were deliberately flown into the Twin Towers of the World Trade Center in New York City, destroying both 110 story skyscrapers within less than two hours, and a third was flown into the Pentagon in Arlington County, Virginia, causing severe damage to the west side of the building. These attacks resulted in the deaths of 221 people (including the 15 hijackers) on board the three planes as well as 2,731 more in and around the targeted buildings. A fourth plane crashed into a field near Shanksville, Pennsylvania, after a revolt by the plane's passengers, killing all 44 people (including the four hijackers) on board. In total, the attacks killed 2,996 people and injured more than 6,000 others. The U.S. stock market closed for four trading days after the attacks (the first time it had an unscheduled closing since the Great Depression). Nine days after the attack, U.S. President George W. Bush called for a "War on Terror" and shortly thereafter launched the War in Afghanistan to find and capture Osama bin Laden, the head of the al-Qaeda organization that mounted the 9/11 attacks.
After the U.S.-led invasion of Iraq in 2003, Iraqi and foreign insurgents carried out waves of suicide bombings. More attacks have been carried out in Iraq (1938 as of mid-2015) than in any other country.
September 11 attacks advance-knowledge conspiracy theories
On December 22, 2010, a United States Federal Judge signed a default judgment holding Iran, the Taliban and al-Qaeda liable following an open court hearing in which the evidence was produced by the plaintiffs' attorneys which they said showed that Iran assisted the hijackers. 9/11 commission members and witnesses who claimed they were Iranian defectors and members of Ministry of Intelligence and National Security and the Iranian Revolutionary Guards also testified during the hearing. The suit "Havlish, et al. v. bin Laden, et al" was brought in 2001 by Fiona Havlish whose husband died in the North Tower. Abolghasem Mesbahi, who claimed he was a former Ministry of Intelligence operative in charge of Iran's espionage operations in Western Europe testified that he was part of a task force that designed contingency plans for unconventional warfare against the United States code-named "Shaitan dar Atash"/"Satan in Flames" which included crashing hijacked passenger airliners into the World Trade Center, the Pentagon, and the White House, and that in the summer of 2001 he received three coded messages telling him to activate the plan. An Iranian government memorandum was presented as evidence that Iran's Supreme Leader Ayatollah Khamenei had pre knowledge of the attacks. Several days after the ruling a spokesperson for Iran's Foreign ministry said charges that Iran "had a hand in planning the attacks and that one of al-Qaeda's members was present inside the country is baseless" and said "With the repetition of such claims to back its political aims the U.S. is putting the peace and security of the world in jeopardy,".