Remember STRATFOR? It's a private intelligence company that, in the late 90's thru early 00's emailed out free "Global Intelligence Updates", until they went full-subscription some years ago.
I kept a number of the more interesting ones, but had not re-read them in years. Here is one I found that was published within hours of the WTC destruction.
I present this to further address the question of "what other knowledgeable public figures was claiming that supplemental explosives were required to cause the collapse". That is all. I do not in any way present this as EVIDENCE that explosives were used.
I copied this message straight out of my in-box, but a quick google turned up this link:
http://www.mail-archive.com/ctrl@listserv.aol.com/msg76269.html
I also found this link,
http://www.halexandria.org/dward250.htm (scroll down), which demonstrates that this STRATFOR email has been publicly addressed before by at least one other person.
11 September 2001
The Intelligence Failure
1745 GMT, 010911
By George Friedman
As of this moment, what is clear is that a substantial number of
civilian aircraft were hijacked this morning by pilots with
sufficient ability to maneuver those multi-engine aircraft into
collisions with major buildings. The flights originated at a
number of airports. Each incident required the presence of at
least one and probably more hijackers, each prepared to die in
the attack.
Mounting an attack of this sort is not simple. In the case of the
World Trade Center, the collapse of the towers indicates massive
delayed explosions. This means either the planes were loaded with
explosives or that massive explosive charges were planted in the
buildings to go off later. This is supposition, but a secondary
explosion is a necessary factor for explaining the collapse.
This means many individuals had to be involved in the operation.
There had to be a coordinated effort spanning several continents,
timed to occur at roughly the same time. At best guess, dozens of
people had to be involved. Messages had to flow, coded or
otherwise. Yet no human intelligence sources appear to have been
among or near the conspirators. No significant messages were
intercepted or decoded.
For U.S. intelligence to have missed an operation of this
magnitude indicates one of two things. First, the competence of
U.S. intelligence is overrated or the willingness of policymakers
to heed warnings has declined. In either case, the system is
badly broken. Alternatively, the sophistication of terrorist
counter-intelligence has improved to such an extent that the
prior level of expertise bought to bear is simply no longer
sufficient.
Whether we are facing a decline in U.S. intelligence capability
or an increase in counter-intelligence blocking the United
States, Sept. 11, 2001, will go down as one of the major
intelligence failures in U.S. history.
George Friedman is the founder and chairman of STRATFOR
I know nothing of George Friedman's or STRATFOR's agenda. He wrote a book last fall entitled "America's Secret War".
http://www.americassecretwar.com/ I do not know if he has publicly made a retraction of this speculation.