Concurrent event: When talking about Ziad Jarrad, the future hijacker / pilot of flight 93 that crashed in Pennsylvania, the 9/11 Commission reported (on page 163): "In September 1997, Jarrah abruptly switched his intended course of study from dentistry to aircraft engineering—at the Technical University of Hamburg-Harburg. His motivation for this decision remains unclear.”
I believe Jarrah's abrupt switch in studies from dentistry in Greifswald, to aircraft engineering 170-miles away in Hamburg marked the coalescing of the Hamburg Cell. I also think it was one of the first logistical actions of a sleeper cell just tasked with attacking the US mainland using hijacked civilian airliners as missiles.
Establishing what date Jarrah ‘abruptly switched his intended course of study’ could help dismiss / validate my claim that 9/11 was inspired by my conversations and meetings in Yemen between 22 and 26 September 1997.
The Hamburg-Yemen connection is further validated by Hamburg Cell member Ramzi bin al Shibh, a Yemeni who (according to the 9/11 Commission report) was travelling between Yemen and Germany in 1997. Ramzi bin al Shibh photo gives a facial recognition match to my dinner companion in Yemen on 25 September, Yousef.