5 September 11 Conspiracy Theories

Some conspiracy theorists subscribe to the idea that the U.S. government did not plan the attacks, but was well aware of the terrorist plot and did nothing to stop it. This is different from the idea that certain officials were warned of a possible attack and didn't give the warnings enough credence to act. Indeed, these theorists believe that officials "let it happen on purpose" (shortened as LIHOP). According to such theories, the U.S. officials consciously allowed the Sept. 11th attacks to go forward, thereby abetting the violent deaths of almost 3,000 people and, as far as they could have predicted, potentially more.

So why would these supposedly sinister, powerful officials consciously condone such horror and allow it to happen? Conspiracy theorists speculate that the officials, including members of the Bush administration, wanted an excuse to invade Afghanistan and Iraq. Theorists point to a document from 2000 by Project for the New American Century (PNAC), a neoconservative think tank. The document states that in order for the military to "fight and decisively win multiple, simultaneous major theatre wars," it must go through a transformation which is "likely to be a long one, absent some catastrophic event -- like a new Pearl Harbor" [source: McConnachie].

Whether one believes that the Bush administration exploited the Sept. 11th attacks for its defense agenda is different from believing that the administration previously knew of and allowed the attacks. Many doubt these officials would be capable of such evil complacence.

In addition to LIHOP theorists, other conspiracy theorists believe the U.S. government, not Osama bin Laden, planned and was primarily responsible for the terrorist attacks. These theorists believe the government "made it happen on purpose" (abbreviated as MIHOP). Why? Just like LIHOPs, MIHOPs speculate that officials in the U.S. government wanted the attacks on Sept. 11th to happen in order to promote involvement in multiple wars.

In addition to motivation, one point that most of both LIHOPs and MIHOPs agree on is that it was very suspicious that military jets did not respond quickly enough to the hijackings. Normally, once a hijacking is confirmed, the military will send fighter jets to escort the plane. The conspiracy theorists say there must have been a "stand down" order that prevented U.S. Air Force jets from coming to the aid of the planes.

But experts argue the delayed response was perfectly reasonable. First, the long chain of communication between air traffic control, the Federal Aviation Administration and the Department of Defense at that time simply took too long to respond to the unprecedented attacks in time. Even when two fighter jets were deployed from Otis Air Force Base in Massachusetts faster than usual in a breach of protocol, the jets had no coordinates for the hijacked Flight 11, because the plane's transponder had been turned off [source: Dunbar]. The North American Aerospace Defense Command (NORAD) also claims that its radars were only prepared to detect threats from outside the continent [source: Popular Mechanics].

The rest of the conspiracy theories we'll cover specifically have to do with MIHOP theories -- that the government actively designed and orchestrated the Sept. 11th attacks. Many conspiracy theorists believe that the information doesn't add up concerning the attack on the Pentagon. Unfortunately, unlike with the World Trade Center, there is no clear video of the plane hitting the Pentagon. Something hit the Pentagon, all right. But these conspiracy theorists don't believe it was a plane. Rather, they say it was some sort of military missile.

Theorists have examined the early photographs of the crash site and believe that the hole made in the building -- which was originally about 75 feet (22.9 meters) wide before more of the building collapsed -- was too small to have been caused by a 757 commercial airplane with a wingspan of over 124 feet (37.8 meters). But experts believe that not only did a wing of plane probably hit the ground before impact with the building, but that the wings would not have been strong enough to neatly penetrate the building [source: Popular Mechanics]. Some find it suspicious that windows above the impact remained intact before the rest of the structure collapsed, but these windows were blast-resistant.

Also, hundreds of witnesses say they saw the plane hit the building. And, if Flight 77 didn't hit the Pentagon, where did it go? More importantly, what happened to the victims who were on it? Perhaps, say theorists, they were put on Flight 93.

If the Sept. 11th attacks were an elaborate government plot, then how do conspiracy theorists explain United Airlines Flight 93, the plane that crashed in an abandoned strip mine near Shanksville, Penn.? Most people believe that passengers on board likely revolted, and the scuffle with the terrorists resulted in the crash. This theory is supported by cockpit recordings.

Conspiracy theorists don't think this story matches the evidence at the crash site, however. Much of the plane at the site was destroyed, and reports of sheet metal and papers found 6 miles (9.7 kilometers) away from the main crash site raise questions. Theorists don't think this could be the result of a normal plane crash, but rather argue that the plane must have been shot down by the government. Popular Mechanics' review of the details determines that debris did not land so far away as these reports indicate, and that all debris landed a reasonable distance from the crash considering the direction in which the wind and the plane were going [source: Popular Mechanics].

Some more outlandish theories claim the plane landed safely in Cleveland, where the passengers were scurried out and perhaps killed, before officials substituted another plane that was shot down in Shanksville. But others argue that identifying information of the plane and human remains prove Flight 93 crashed in Shanksville. They also say this conspiracy theory is mostly based on an early bogus news report (of which there were many that day) that Flight 93 landed in Cleveland.

Perhaps the most famous conspiracy theories surrounding Sept. 11 have to do with the most devastating attack that day: the planes that flew into the World Trade Center. Conspiracy theorists believe that the buildings would not and did not collapse as a result of being hit by planes, but rather by controlled demolition.

The documentary "Loose Change" argues the government planted explosives in the building ahead of time that ensured the collapse, saying that the steel structures would have normally withstood the impact and fire. However, others, including a Nova PBS documentary "Why the Towers Fell," argue that the unique construction of the towers and the way they were hit resulted in the collapse.

Theorists often point to the fact that jet fuel doesn't burn hot enough to melt steel. But others respond that the fire undoubtedly ignited other combustibles in the office building, like paper, carpet and electronics, that would have fed the fire. Also, the force of the impact, according to experts, probably blew off the fireproofing foam covering the floor trusses, and the force of the fire would only have to weaken the steel to cause a "pancaking" collapse.

Considering everything, in order to pull this elaborate conspiracy off, the government would have needed to use an enormous number of accomplices who are now keeping quiet. For many, this is harder to believe than the idea that 19 hijackers led by a known enemy of the U.S. were responsible.