I do disagree with him on one point:
Not enough commentaries have been written about the absolute stupidity and uselessness of the 9/11 attacks—specifically about them being absolutely stupid and useless even from a sane global jihadist’s point of view. While an attack on the Pentagon might be rationalized in military or Clausewitzean terms, the more successful attack on the World Trade Center was totally devoid of real military or strategic value. There were no follow-up attacks. The attacks were part of no greater plan. The slaughter of 3,000 American civilians did absolutely nothing to further any jihadist "goals"—whether it be the removal of American troops from "sacred Muslim soil" or the weakening of the Arab regimes that were the jihadists’ real enemies.
Killing 3,000 Americans directly contributed to two of Al Qaeda's goals:
1. Breaking the will of the American people would lead to a pullback from the MidEast and a cut-off of aid to the governments there. This had exactly the opposite result, but given the examples of Lebanon and Somalia it was a reasonable expectation for them. Given the number of people in the USA advocating such a withdrawal they may not have realized how badly it backfired for a year or more.
2. Presenting Osama bin Laden as the greatest killer of infidels alive today elevated his stature in the Muslim world--look up the number of kids named Osama recently--and made him the obvious choice for a new Caliph. Uniting the Arabs in a Caliphate requires someone for them to follow, and "Why Osama?" now has a clear answer.
Neither of those required immediate follow-on attacks. For #1 their best response was to wait for us to withdraw and not make any attacks, boosting the arguments of the pacificists. #2 required internal maneuvering in Arab nations, and there were attacks there. So even if their ideology is fantasy-based their actions can aim at achievable goals.
Simmons found the nastiness coming out of the discussion on his boards "mildly depressing." He goes through various points of view and picks apart the logical flaws in their arguments. I don't worry so much about the logic behind the arguments as the unwillingness to accept new information or change conclusions.
[Hattip to bitpig]