The story of Iran's involvement in 9/11 begins in January 2001. That is when Ayman al-Zawahiri, bin Laden’s second in command, came to Tehran with a request for operational support for the attacks. Until that moment, 9/11 was nothing but a plan and a team of raw recruits loosely organized into independent cells within America. The plan was going, but it was not going well: It was changing almost daily. There weren’t enough pilots. The pilots weren’t completely trained. Some of the conspirators hardly spoke English. Some of them had difficult personalities. They quarreled. One almost quit. They were naive and careless. The INS and FBI were already on their trail.
What the conspirators needed was the steady hand of a cadre of experienced security, espionage, and foreign terrorism agents. Such mentors and managers can only be found within the government bureaucracy of a major state: one with unlimited funds, and consulates and contacts in many countries. That is why Zawahiri turned to Iran.
The government of Iran generally deliberates carefully before making a major decision. But the Iranians must have jumped for joy when they heard what al-Qaeda had been planning. Here was a once-in-a-lifetime opportunity for Iran to deal a massive blow to its sworn enemies, Israel and the United States. (As late as January 2001, al-Qaeda was planning to strike in both countries on the same day.) Even better, so long as Iran covered its own tracks, al-Qaeda and bin Laden would take the blame. Iran would get off scot free. It could then play this game again and again. In the process, bin Laden would become a folk hero among oppressed Muslims worldwide, thereby uniting all of militant Islam. This would bring Iran closer to the day when it could emerge from the shadows and seize the leadership of the Muslim world.
Iran Tries to Expropriate the Plan, al-Qaeda, and bin Laden
This windfall was too important to entrust to bin Laden. So the Iranians began deliberately to expropriate from al-Qaeda…
1. The planning and execution of the attacks;
2. Al-Qaeda, itself;
3. And Osama bin Laden.
By the end of the year, they believed that they had succeeded in stealing all three. Here is where the story gets strange:
The Iranians did, in fact, obtain items 2 and 3. They thought they had obtained Item 1 as well; but bin Laden was cagier than the Iranians. In exchange for operational support from the Iranian government, bin Laden let them think that they were in charge. The Iranians immediately began to make demands. In particular, they wanted to greatly expand the list of targets, and were willing to foot the bill in order to do so. But bin Laden had worked too long and too hard for his triumph against the West. He was not about to jeopardize the attack by overreaching. Bin Laden appeared to acquiesce; but later he informed the Iranians that he simply could not get enough hijackers into America to carry out the expanded plan. (This wasn't entirely disingenuous; in fact, al-Qaeda did try to get more conspirators into the United States, but the additional hijackers were unable to get visas. One succeeded in entering America, only to be turned back by the Immigration and Naturalization Service (INS.)) In the meantime, bin Laden made good use of the diplomatic reach and money laundering expertise of the Iranian government.
While Iran only thought that it had expropriated the plan, it did in fact manage to expropriate al-Qaeda and bin Laden, himself. By November of 2001, the American-led Coalition had toppled the Taliban and was now bombing al-Qaeda strongholds, training camps, and safe houses. Bin Laden and his top-level commanders, a large number of al-Qaeda fighters, and their families fled through Iran to Iraqi Kurdistan. Waiting for them in Iraq was a fall-back stronghold that had previously been secured for bin Laden by Abu Musab al-Zarqawi. But the refugees never made it to Iraq. They crossed the border from Afghanistan into Iran, and, under the protection of the Islamic Revolutionary Guards Corps (IRGC,) traveled as far west as Tehran. There, as we will see, the Iranian government enticed them to stay. They have been living there ever since.
Why the Warnings were Ineffective
We can now understand why Hamid Reza Zakeri and Abdolghassen Mesbahi were so convinced that Iran was going to attack the United States. Their informants inside the Iranian government saw plentiful evidence. As we will see, Iran established operational centers in Karaj and Tehran that included models and photographs of the targets. Hundreds of government employees — including Zakeri, himself — had seen the models. For many months after the attacks, senior Iranian officials bragged that it was Iran that had brought America to its knees. Only when the 9/11 Commission Report was published in July 2004 did the Iranians have to confront the reality that they had contributed little to the attack's success.
We can also understand why the CIA had trouble accepting the warnings they received from Zakeri and Mesbahi. Why would a relatively small nation attack the world's only superpower? It seemed suicidal. America would counterattack with overwhelming force. On the other hand, during the summer of 2001, the CIA was receiving daily bulletins suggesting that al-Qaeda was planning something big. But Zakeri and Mesbahi either failed to realize or failed to mention that Iran was attacking America through al-Qaeda.
Neither the hijackers, nor the Hamburg Cell, nor their recruiters, nor the money launderers knew that Iran was involved. Neither did the governments of Saudi Arabia, the United Arab Emirates, Afghanistan, or Pakistan. Only the highest officials of the Iranian government knew.