Namely, assuming that what came was caused by what happened before.
This is a particularly blatant illustration of the fallacy because there is no good evidence that the toppled Ba'thist regime cooperated with al-Qaeda. Feith clings to his talisman of purported cooperation, which he then uses to claim a logical connection: post-invasion cooperation between some insurgents and al-Qaeda oriented jihadists logically flowed from cooperation (which did not exist) between the toppled regime and al-Qaeda.
Douglas J. Feith - Tough Questions We Were Right to Ask - washingtonpost.com: "In evaluating our policy toward Iraq after Sept. 11, 2001, my office realized that CIA analysts were suppressing some of their information. They excluded reports conflicting with their favored theory: that the secular Iraqi Baathist regime would not cooperate with al-Qaeda jihadists. (We now face a strategic alliance of jihadists and former Baathists in Iraq.) Pentagon officials did not buy that theory, and in 2002 they gave a briefing that reflected their skepticism."