If you follow the money, the men in the middle of the disbursing of funds to the 9/11 hijackers were United Airlines Flight 175 hijacker-pilot Marwan al-Shehhi and a UAE-based computer specialist Ali Abdul Aziz Ali (Ali), who ultimately received the money from his uncle, 9/11 mastermind Khalid Sheikh Muhammad (KSM).

In the late 1990s and early 2000s, Al Qaeda was able to raise about $30 million a year, mostly from zakat and sadaqa from wealthy Arab donors and other supportive Muslims around the world. The money was funneled through Islamic charities—often charitable foundations backed directly by the Saudi government—and through hawala, the traditional Islamic system of transferring money without physically having to transfer cash. The same methods continue being used to fund Al Qaeda and its offshoots today.

Of that $30 million, $10-$20 million was estimated by the 9/11 Commission to have been given annually to the Taliban. The…