No propaganda was required to convince people that 9/11 was the result of malice on Al Qaeda's part

Flatly false. The historical background you cite in your later post is part of the campaign to convince people that al-Qaeda was responsible for 9/11. There has been a double narrative, one of intent and another of capability, extending back for quite some time.

The FBI had an informant on Ramzi Yousef and the associated 1993 bombers, and people in key positions within the FBI and CIA foiled attempts to foil the bombing. Meaning it was allowed to happen. In every case where a domestic or foreign al-Qaeda terror plot was involved, the intelligence community was aware of it. It's the height of delusion to otherwise of the country with the largest information dragnet in the world. It was aware in advance of the '93 Trade Center bomb plot, the '95 Oklahoma City plot, the USS Cole bomb plot, and the 9/11 attacks, in part because it enabled all four of those. Yes bin Laden threatened the West, but he was incapable of striking within the United States.

al-Qaeda was/is not capable of penetrating US air defense with hijacked airplanes. It's the height of delusion to think that nineteen suspects would not trigger red flags of the largest intelligence dragnet in history, under the FBI, CIA, the domestic counter-terrorism program Able Danger, Germany's intelligence service, and/or Saudi Arabian intelligence. These men:

• Trained at CIA-linked aviation schools, after failing out of other legitimate flight schools in the country
• Majority had weak to below-average piloting skills
• Flight 77 alleged hijackers lived in a hotel outside NSA headquarters!
• were able to over-power passengers, crew (who outnumbered them, in the best case, 18:1, and the worst case 6:1) and Navy-trained fighter pilots who had experience in aerial combat maneuvers that could easily throw off the balance of an aspiring hijacker (e.g. a barrel roll) which a Boeing 757/67 airframe is certainly capable of...and overpowered them with box-cutters, while standing on average between 5'5" and 5'7"
• were able to fly on long detours before reaching their targets without being intercepted by fighter jets.
• were able to direct planes through "radar gaps", and turned off transponders precisely when the planes crossed the borders through these gaps -- details widely unknown even to air traffic controllers.
• No obvious signs of struggle in a supposed take-over apart from a deviation in flight path and disabled transponder. No radio emergency calls, no hijack squawk code. Only case of hijack struggle was Flight 93, the details of which are suspect.

The hijacker pilot of Flight 77, Hani Hanjour, who:

• was unable to land and control a single-engine Cessna
• Barely managed to complete initial training for a Boeing 737
• told by his instructors to quit training for a Boeing 737 license
• "had no idea what was going on"
• frequently skipped classes
• called a "waste of resources" by his flight instructors
• struggled with basic English, proficiency in which is a basic certificate requirement under FAA guidelines, was suddenly able to...

...in addition to the problems with hijacking a passenger jet...also performed a 330-degree, 7000 foot, 3-mile radius descending corkscrew turn in a Boeing 757 to hit the Pentagon in its recently renovated, largely unoccupied West wing, greatly limiting the potential casualties. Why didn't he aim for the 29 acres of rooftop, which would have caused far more damage and far more casualties?

Many experienced aviation professionals (pilots, engineers) commented soon after the events on the extensive skill demanded for the three attacks...none of which any of the alleged hijackers had.

Disregarding the immediate problems encountered with overcoming air defense and hijacking a passenger jet, one would reasonably think that a determined al-Qaeda would choose competent pilots to use as "flying missiles".

Yes, much propaganda was required to lull people into thinking al-Qaeda was capable of 9/11, because it wasn't capable. Malice doesn't even enter into the equation, nor do neoconservative priorities.