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.
Central Intelligence Agency
In 1999, CIA chief George Tenet launched a grand "Plan" to deal with al-Qaeda. The Counterterrorist Center, its new chief Cofer Black and the center's bin Laden unit were the Plan's developers and executors. Once it was prepared Tenet assigned CIA intelligence chief Charles E. Allen to set up a "Qaeda cell" to oversee its tactical execution. In 2000, the CIA and USAF jointly ran a series of flights over Afghanistan with a small remote-controlled reconnaissance drone, the Predator; they obtained probable photos of bin Laden. Cofer Black and others became advocates of arming the Predator with missiles to try to assassinate bin Laden and other al-Qaeda leaders. After the Cabinet-level Principals Committee meeting on terrorism of September 4, 2001, the CIA resumed reconnaissance flights, the drones now being weapons-capable.On September 11, 2001, 19 Al-Qaeda members hijacked four passenger jets within the Northeastern United States in a series of coordinated terrorist attacks. Two planes crashed into the Twin Towers of the World Trade Center in New York City, the third into the Pentagon in Arlington County, Virginia, and the fourth inadvertently into a field near Shanksville, Pennsylvania. The attacks cost the lives of 2,996 people (including the 19 hijackers), caused the destruction of the Twin Towers, and damaged the western side of the Pentagon. Soon after 9/11, "The New York Times" released a story stating that the CIA's New York field office was destroyed in the wake of the attacks. According to unnamed CIA sources, while first responders, military personnel and volunteers were conducting rescue efforts at the World Trade Center site, a special CIA team was searching the rubble for both digital and paper copies of classified documents. This was done according to well-rehearsed document recovery procedures put in place after the Iranian takeover of the United States Embassy in Tehran in 1979. While it was not confirmed whether the agency was able to retrieve the classified information, it is known that all agents present that day fled the building safely.