According to the  9/11 Commission report, many of the 9/11 hijackers were known to have traveled in and out of Iran prior to the 9/11 attacks. The report also noted that Iran had a history of allowing al-Qaeda operatives to travel back and forth between Iran and Afghanistan [to their training camps], and that Iranian border agents were ordered not to stamp the passports of al Qaeda operatives, which thereby facilitated their travel, and also helped conceal their whereabouts and their identities.
In 2011, members of the 9/11 Commission testified that Iranian border agents refrained from stamping the passports of 8 to 10 of the 9/11 hijackers because evidence of travel through Iran would have prevented the hijackers from obtaining visas at U.S. embassies abroad or gaining entry into the United States. The 9/11 commission report also noted that al-Qaeda operatives had long maintained contact with Iranian intelligence officials.
Additionally, the Telegraph-UK reported in 2008 that a letter "signed by Ayman al-Zawahiri, [then]-al-Qaeda's second in command - [which was] written after the American embassy in Yemen was attacked by simultaneous suicide car bombs - thanked the leadership of Iran's Revolutionary Guards for providing assistance to al-Qaeda to set up its terrorist network in Yemen."
"In the letter, al-Qaeda's leadership pays tribute to Iran's generosity, stating that without its 'monetary and infrastructure assistance' it would have not been possible for the group to carry out the terror attacks. It also thanked Iran for having the 'vision' to help the terror organization establish new bases in Yemen."
The AFP reported in December of 2010:
A member of the elite al-Quds force of Iran's Revolutionary Guard has been captured in southern Afghanistan accused of cross-border weapons smuggling... British newspaper The Times reported that Iran has released a string of senior Al-Qaeda militants from custody so they can help the network rebuild in the Afghanistan-Pakistan border areas.Among the numerous reports detailing Iran's support to the Afghan insurgency was the following report from Fox News:
The newspaper quoted anonymous Pakistani and Middle Eastern officials accusing Iran of giving covert support to the Islamist militants, often through the Revolutionary Guards...
The discovery of a weapons cache in western Afghanistan has raised concerns that Iran is interfering in the war-torn country, much like it did in Iraq, by supplying weapons used to attack and kill U.S. and coalition troops.The State Department noted in one of its annual reports on terrorism:
Afghan and NATO forces uncovered the weapons cache on Aug. 29 in Herat. It included a small number of Iranian-made "explosively formed penetrators," hyper-powerful roadside bombs similar to the weapons used to kill U.S. forces in Iraq, a senior U.S. Defense Official told FOX News.
Also seized during the raid were 107 Iranian-made BM-1 rockets and dozens of blocks of Iranian C4 plastic explosives...
Iran’s IRGC Qods Force provided assistance to the Taliban in Afghanistan. The Qods Force provided training to the Taliban on small unit tactics, small arms, explosives, and indirect fire ammunition, rocket propelled grenades, mortar rounds, 107mm rockets, and plastic explosives....In short, Iran's ties to Al Qaeda and to the Iraqi and Afghan insurgency has been well-documented. Which leads us to the following report that the US Department of Treasury released last week about "al-Qaida's Iran network" and "a key Iran-based al-Qaida facilitator."
The US Department of Treasury announced last week that it had designated 3 officers of the Iranian Revolutionary Guard Qods Force as terrorists for their involvement in planning and executing terrorist attacks in Afghanistan.
The Treasury Department also announced the designation of Jafar al-Uzbeki, "a key Iran-based al-Qaida facilitator who supports al-Qaida’s vital facilitation network in Iran, that operates there with the knowledge of Iranian authorities." Al-Uzbeki provided "logistical support and funding to al-Qa’ida's Iran-based network" and he "has assisted extremists and operatives transiting Iran on their way into and out of Pakistan and Afghanistan." Al-Uzbeki "has provided visas and passports to numerous foreign fighters, including al-Qaida recruits, to facilitate their travel."
The US Department of Treasury report also notes that al Qaida's Iran-based network is assisting the Al Qaeda-linked rebels in Syria.
According to the report, "Al-Uzbeki also provided funding to Yasin al-Suri, who has resumed leadership of al-Qaida's Iran-based network. As head al-Qaida facilitator in Iran, Yasin al-Suri is responsible for overseeing al-Qaida efforts to transfer experienced operatives and leaders from Pakistan to Syria, organizing and maintaining routes by which new recruits can travel to Syria..., and assisting in the movement of al-Qaida external operatives to the West."
"Al-Qaida’s network in Iran has facilitated the transfer of funds... to al-Qaida core and other affiliated elements, including the al-Nusrah Front in Syria..."
The question, however, arises: Despite the close ties between Iran and al-Qaeda - the one country in which the two sides are at odds is Syria. Although Iran is eagerly assisting al Qaeda in its efforts to subvert the governments of various countries around the globe - Syria is the exception, due to the fact that Iran relies heavily on the Syrian regime's support. Moreover, with regards to the current fighting in Syria, Iran has openly proclaimed their support for Bashar Assad and the Syrian regime.
Hence, the question arises: Why is Iran assisting the [al-Qaeda] al-Nusrah front in Syria?
I will proffer two explanations to solve this quandary. Both explanations might be correct, but I believe the second explanation is more on the mark:
1) There is no guarantee that Syrian President Bashar Assad will remain in power - although his hold on power seems to get stronger each passing day. Nevertheless, there might ultimately be a power sharing agreement between the the current government and the rebel forces - or perhaps the current government and its affiliates will be completely removed from power. Either way, the Iranian regime is seeking to ensure that the al Qaeda-linked rebels, and not the western-backed rebels, are the dominant power within the rebel forces. This will ensure that a Syrian government comprised of the rebel forces will never become an ally to the West, but rather an Iranian ally, or an Iranian proxy. But ultimately the Iranian regime is standing behind the Syrian regime; it is merely lending some assistance to the al Qaeda rebels for the reason I just cited: to strengthen the extremists within the rebel forces and to ensure that Iran' does not lose its influence in Syria and that the west never gains influence in Syria.
2) The Iranian regime is seeking to ensure that the Al Qaeda-linked rebels, and not the western-backed rebels, are the dominant power within the rebel forces because this will both dissuade and deter the west from backing the rebels. Hence, although the Iranian regime and its Qods forces are completely supportive of the Assad regime, the Iranian regime has decided to lend some assistance to the [al-Qaeda] al-Nusrah front in order to weaken the position of the more moderate rebels and to deter the west from backing the rebel forces.
And now you know the rest of the story............
It is worthy to note that despite Iran's well-documented ties to al Qaeda, President Obama is nevertheless befriending the Iranian regime, al Qaeda's close ally - which might leave some scratching their heads in bewilderment, and others nodding their heads [in disgust], totally unsurprised..........