The two professors may have trouble seeing how the World Trade Center towers would have been brought down just because they were hit dead on with large airplanes loaded with jet fuel. I have a hard time seeing how it would have been possible for anyone to have managed to set all the charges that would have been necessary in buildings 1, 2, and 7 without being detected by security. I also have a hard time seeing why implosion would make any sense once the planes had crashed into the buildings. If a casus belli against the Islamofascists was needed, why wasn’t the hijacking of four planes sufficient?