According to Paul Craig Roberts:
Kevin Ryan, a science/engineering employee of the firm that certified the steel used in the construction of the World Trade Center skyscrapers, realized that the official explanation of the destruction of the three skyscrapers was false. Steel does not, and cannot, behave in the way that the official explanation says.Ryan lists a number of ties that key US ruling class figures and well-connected security personnel of the FBI and CIA had with Saudi Arabians who were involved in the 9/11 attack. Following this list, he concludes:
...it is not surprising that people who hear claims of Saudi involvement in 9/11 wonder why the discussion remains so limited and always avoids the glaring implications those claims should entail.