The following excerpt from a piece by Bill Christison provides a good 101 on 9/11 from someone who used to actually read tea leaves for The Company. From 1950 to 1979, Christison was an Analyst for the CIA. Beginning in the early 70s he served as National Intelligence Officer and was a principal adviser to the Director of Central Intelligence on Southeast Asia, South Asia and Africa. Before retiring in 1979 he was Director of the CIA's Office of Regional and Political Analysis.

From August 15, 2006
“Stop Belittling the Theories About September 11,” By Bill Christison

…Why is it important that we not let the so-called conspiracy theories surrounding 9/11 be drowned out? After spending the better part of the last five years treating these theories with utmost skepticism, I have devoted serious time to actually studying them in recent months, and have also carefully watched several videos that are available on the subject. I have come to believe that significant parts of the 9/11 theories are true, and that therefore significant parts of the “official story" put out by the U.S. government and the 9/11 Commission are false. I now think there is persuasive evidence that the events of September did not unfold as the Bush administration and the 9/11 Commission would have us believe. The items below highlight the major questions surrounding 9/11 but do not constitute a detailed recounting of the evidence available.
ONE: An airliner almost certainly did not hit The Pentagon. Hard physical evidence supports this conclusion; among other things, the hole in the Pentagon was considerably smaller than an airliner would create. The building was thus presumably hit by something smaller, possibly a missile, or a drone or, less possibly, a smaller manned aircraft. Absolutely no information is available on what happened to the original aircraft (American Airlines Flight 77), the crew, the "hijackers," and the passengers. The "official story," as it appeared in The 9/11 Commission Report simply says, "At 9:37:46, American Airlines Flight 77 crashed into the Pentagon, traveling at approximately 530 miles per hour. All on board, as well as many civilians and military personnel in the building, were killed." This allows readers to assume that pieces of the aircraft and some bodies of passengers were found in the rubble of the crash, but information so far released by the government does not show that such evidence was in fact found. The story put out by the Pentagon is that the plane and its passengers were incinerated; yet video footage of offices in the Pentagon situated at the edge of the hole clearly shows office furniture undamaged. The size of the hole in the Pentagon wall still remains as valid evidence and so far seems irrefutable.
TWO: The North and South Towers of the World Trade Center almost certainly did not collapse and fall to earth because hijacked aircraft hit them. A plane did not hit Building 7 of the Center, which also collapsed. All three were most probably destroyed by controlled demolition charges placed in the buildings before 9/11. A substantial volume of evidence shows that typical residues and byproducts from such demolition charges were present in the three buildings after they collapsed. The quality of the research done on this subject is quite impressive.
If the judgments made on Points ONE and TWO above are correct, they raise many "Who done it" questions and strongly suggest that some unnamed persons or groups either inside or with ties to the government were actively creating a "Pearl Harbor" event, most likely to gain public support for the aggressive foreign policies that followed—policies that would, first, “transform" the entire Middle East, and second, expand U.S. global domination.
These first two points provide the strongest evidence available that the “official story" of 9/11 is not true. If the government could prove this evidence false, and its own story on these points correct, all the other data and speculation supporting the conspiracy theories would be undermined.It has provided no such proof and no answers to growing questions. Other, less important points supporting the theories include the
following.
THREE: For at least one hour and 45 minutes after the hijacking of the first aircraft was known, U.S. air defense authorities failed to take meaningful action. This strikes some "conspiracy theorists" as valid evidence that the U.S. Air Force was deliberately restrained from acting. Maybe so, but my own skepticism tells me that the inefficiency of U.S. defense forces is likely to be just as plausible an explanation.
FOUR: Some of the theorists believe that the 19 named hijackers were not actually the hijackers. One claim is that the names of the hijackers were not on the manifests of any of the four aircraft.
FIVE: None of the 19 hijackers' bodies were ever autopsied (since they were allegedly totally destroyed in the crashes, including even the people in the Pennsylvania crash).
SIX: At least five of the alleged hijackers (or persons with identical
names) have since turned up alive in the Middle East. Nonetheless, the FBI has never bothered to re-investigate or revise the list of hijackers. Does this suggest that the FBI knows that no one in the administration is interested in reopening any further investigations?
SEVEN: Numerous pilots have allegedly told the theorists that none of the 19 hijackers could have flown the airliners well enough to hit the World Trade Center towers and the Pentagon with as much accuracy as was displayed. The debate on this issue simply raises more doubt about the government's charge that the people it has named as hijackers are the real hijackers.
EIGHT: No one, except possibly government investigators who are not talking, has seen the plane that went down in Pennsylvania. Some of the conspiracy theorists suggest that it was deliberately destroyed before it hit the ground; others suggest that the plane actually landed in Cleveland and that passengers then were whisked away to some unknown destination. What happened to them at that point is simply a large question mark that makes it more difficult to believe this particular scenario.
NINE: Machinations in the U.S. stock market in the days before 9/11 suggest that some inside players in the market knew or suspected that United and American Airlines stock would soon drop. Two of the four of the aircraft involved in 9/11 were, of course, United planes and the other two were American Airlines planes.
It should be reemphasized that these items do not make up a complete list of all the charges made by the theorists, but they are a good sample. Anyone interested in perhaps the best summary of these charges should watch the video "Loose Change."
To repeat, points ONE and TWO above are the most important. If something other than an airliner actually did hit the Pentagon on 9/11, and if the North and South Towers of the World Trade Center actually were dropped to the ground by controlled demolitions rather than by anything connected to the hijackings, the untrue stories peddled by The 9/11 Commission Report are clearly susceptible of being turned into major political issues….