First, let's get the facts on Saudi and Iranian involvement in 9/11

Iran had an alliance with al-Qaeda beginning in the early 1990s. It principally included training by Hezbollah (the Beirut-based terrorist faction created and controlled by Iran’s Islamic Revolutionary Guard Corps) and such joint ventures as the 1996 Khobar Towers attack, in which 19 U.S. airmen were killed (and the FBI’s investigation of which was obstructed by the Saudi government). Toward the conclusion of its probe (and thus without time to investigate the matter fully), the 9/11 Commission learned that Iran had provided critical assistance to the suicide hijackers by allowing them to transit through Iran and Lebanon as they moved from obtaining travel documents in Saudi Arabia (Saudi passports and U.S. visas) to training for the attacks in al-Qaeda’s Afghan safe havens.

Indeed, we now know that Iran’s assistance was overseen by none less than Imad Mugniyah, the now-deceased Hezbollah master terrorist who spent much of his life killing Americans, most notoriously in the Beirut marine-barracks bombing in 1983, and almost certainly at Khobar Towers. In October 2000, Mugniyah went to Saudi Arabia to “coordinate activities” (as the 9/11 Commission put it) with the suicide hijackers. (See 9/11 Commission Report at page 240, as well as affidavits of former CIA officers and a 9/11 Commission staffer, here and here). Thereafter, Mugniyah and other senior Hezbollah members accompanied the “muscle hijackers” on flights through Iran and Lebanon.

By enabling the hijackers to cross through these countries without having their passports stamped – an Iranian or Lebanese stamp being a telltale sign of potential terrorist training – Iran made it much more likely that the jihadists’ applications for Saudi passports and U.S. visas would be approved, as they were. That is why, on the topic of potential Iranian complicity in the plot, the 9/11 Commission wrote, “We believe this topic requires further investigation by the U.S. government.”

The plea has fallen on deaf ears. In fact, thanks to Obama’s Iranian nuclear deal, our government is no longer content to be willfully blind; it is knowingly and materially supporting Tehran’s terror promotion, to the tune of tens of millions of dollars.