While the State Department's Patterns of Global Terrorism—2003 report  labeled Iran "the most active state sponsor of terrorism in 2003," the Bush administration has yet to agree on a national security presidential directive to define U.S. policy toward the Islamic Republic. Meanwhile, Tehran continues to edge closer to nuclear capability.
The following are excerpts from the 9/11 Commission Report, an unclassified version of which was released to the public on July 22, 2004. The commission interviewed more than 1,000 people in ten countries and conducted an unprecedented review of U.S. intelligence. Among its findings, excerpted below, was evidence of a significant and continuing relationship between al-Qaeda and the Islamic Republic of Iran.—The Editors
Iran and Khobar Towers—1996
On June 26, 1996, a truck bomb ripped through an apartment complex in Dhahran, Saudi Arabia, killing nineteen U.S. servicemen. In 1997, the Washington Post reported that the Saudi Hezbollah operatives suspected of carrying out the attack were associated with Brigadier Ahmad Sharifi, an Islamic Revolutionary Guard Corps commander. In passing, the 9-11 Commission reiterated the likelihood that Iranian officials played a major role in attacking U.S. forces:
In June 1996, an enormous truck bomb detonated in the Khobar Towers residential complex in Dhahran, Saudi Arabia, that housed U.S. Air Force personnel. Nineteen Americans were killed, and 372 were wounded. The operation was carried out principally, perhaps exclusively, by Saudi Hezbollah, an organization that had received support from the government of Iran. While the evidence of Iranian involvement is strong, there are also signs that al Qaeda played some role, as yet unknown.
Did Iran Train Al-Qaeda?
Between 1991 and 1996, Osama bin Laden lived in Sudan where he was protected by Hassan Abdullah at-Turabi, the leader of Sudan's National Islamic Front, an Islamist movement. According to the 9-11 Commission, Sudanese officials facilitated meetings between al-Qaeda operatives and Iranian officials, a relationship which blossomed into tactical training:
Turabi sought to persuade Shiites and Sunnis to put aside their divisions and join against the common enemy. In late 1991 or 1992, discussions in Sudan between al Qaeda and Iranian operatives led to an informal agreement to cooperate in providing support—even if only training—for actions carried out primarily against Israel and the United States. Not long afterward, senior al Qaeda operatives and trainers traveled to Iran to receive training in explosives. In the fall of 1993, another such delegation went to the Bekaa Valley in Lebanon for further training in explosives as well as in intelligence and security. Bin Ladin reportedly showed particular interest in learning how to use truck bombs such as the one that had killed 241 U.S. Marines in Lebanon in 1983. The relationship between al Qaeda and Iran demonstrated that Sunni-Shia divisions did not necessarily pose an insurmountable barrier to cooperation in terrorist operations.
Did Iran Aid Terrorist Transit?
In 1996, after the Taliban seized power, Osama bin Laden relocated to Afghanistan where he established a number of terrorist training camps. Al-Qaeda training attracted a steady stream of young Islamists, many of whom transited Iran. While Iranian border officials normally stamp passports, they made an exception for many Al-Qaeda terrorists. The 9-11 Commission explained how this facilitated Al-Qaeda operations:
Certain al Qaeda members were charged with organizing passport collection schemes to keep the pipeline of fraudulent documents flowing. To this end, al Qaeda required jihadists to turn in their passports before going to the front lines in Afghanistan. If they were killed, their passports were recycled for use. The operational mission training course taught operatives how to forge documents. Certain passport alteration methods, which included substituting photos and erasing and adding travel cachets, were also taught. Manuals demonstrating the technique for "cleaning" visas were reportedly circulated among operatives. Mohammed Atta [a 9-11 hijacker] and Zakariya Essabar [an Al-Qaeda member whose U.S. visa was rejected, preventing him from participating in the 9-11 hijackings] were reported to have been trained in passport alteration. The purpose of all this training was twofold: to develop an institutional capacity for document forgery and to enable operatives to make necessary adjustments in the field. It was well-known, for example, that if a Saudi traveled to Afghanistan via Pakistan, then on his return to Saudi Arabia his passport, bearing a Pakistani stamp, would be confiscated. So operatives either erased the Pakistani visas from their passports or traveled through Iran, which did not stamp visas directly into passports.
Iranian Support for the 9/11 Terrorists
Iranian support for Al-Qaeda continued to increase, even as Clinton administration officials sought to extend an olive branch to the Islamic Republic. The 9-11 Commission documented at length Iran's continuing assistance to Al-Qaeda and recommended that the U.S. government further investigate Iranian links to Al-Qaeda:
While in Sudan, senior managers in al Qaeda maintained contacts with Iran and the Iranian-supported worldwide terrorist organization Hezbollah, which is based mainly in southern Lebanon and Beirut. Al Qaeda members received advice and training from Hezbollah. Intelligence indicates the persistence of contacts between Iranian security officials and senior al Qaeda figures after bin Ladin's return to Afghanistan. Khallad [bin Attash, a high-level Al-Qaeda operative] has said that Iran made a concerted effort to strengthen relations with al Qaeda after the October 2000 attack on the USS Cole, but was rebuffed because bin Ladin did not want to alienate his supporters in Saudi Arabia. Khallad and other detainees have described the willingness of Iranian officials to facilitate the travel of al Qaeda members through Iran, on their way to and from Afghanistan. For example, Iranian border inspectors would be told not to place telltale stamps in the passports of these travelers. Such arrangements were particularly beneficial to Saudi members of al Qaeda. Our knowledge of the international travels of the al Qaeda operatives selected for the 9/11 operation remains fragmentary. But we now have evidence suggesting that 8 to 10 of the 14 Saudi "muscle" operatives traveled into or out of Iran between October 2000 and February 2001.
In October 2000, a senior operative of Hezbollah visited Saudi Arabia to coordinate activities there. He also planned to assist individuals in Saudi Arabia in traveling to Iran during November. A top Hezbollah commander and Saudi Hezbollah contacts were involved. Also in October 2000, two future muscle hijackers, Mohand al Shehri and Hamza al Ghamdi, flew from Iran to Kuwait. In November, Ahmed al Ghamdi apparently flew to Beirut, traveling—perhaps by coincidence—on the same flight as a senior Hezbollah operative. Also, in November, Salem al Hazmi apparently flew from Saudi Arabia to Beirut.
In mid-November, we believe, three of the future muscle hijackers, Wail al Shehri, Waleed al Shehri, and Ahmed al Nami, all of whom had obtained their U.S. visas in late October, traveled in a group from Saudi Arabia to Beirut and then onward to Iran. An associate of a senior Hezbollah operative was on the same flight that took the future hijackers to Iran. Hezbollah officials in Beirut and Iran were expecting the arrival of a group during the same time period. The travel of this group was important enough to merit the attention of senior figures in Hezbollah.
Later in November, two future muscle hijackers, Satam al Suqami and Majed Moqed, flew into Iran from Bahrain. In February 2001, Khalid al Mihdhar may have taken a flight from Syria to Iran, and then traveled further within Iran to a point near the Afghan border.
KSM [Khalid Sheikh Mohammed, the alleged mastermind of the 9-11 attacks who is now in custody] and [Ramzi] Binalshibh [an al Qaeda operative captured in Pakistan a year after the attacks who acknowledged a planning role] have confirmed that several of the 9/11 hijackers (at least eight, according to Binalshibh) transited Iran on their way to or from Afghanistan, taking advantage of the Iranian practice of not stamping Saudi passports. They deny any other reason for the hijackers' travel to Iran. They also deny any relationship between the hijackers and Hezbollah.
In sum, there is strong evidence that Iran facilitated the transit of al Qaeda members into and out of Afghanistan before 9/11, and that some of these were future 9/11 hijackers. There also is circumstantial evidence that senior Hezbollah operatives were closely tracking the travel of some of these future muscle hijackers into Iran in November 2000. However, we cannot rule out the possibility of a remarkable coincidence—that is, that Hezbollah was actually focusing on some other group of individuals traveling from Saudi Arabia during this same time frame, rather than the future hijackers.
We have found no evidence that Iran or Hezbollah was aware of the planning for what later became the 9/11 attack. At the time of their travel through Iran, the al Qaeda operatives themselves were probably not aware of the specific details of their future operation.
After 9/11, Iran and Hezbollah wished to conceal any past evidence of cooperation with Sunni terrorists associated with al Qaeda. A senior Hezbollah official disclaimed any Hezbollah involvement in 9/11. We believe this topic requires further investigation by the U.S. government.
 Patterns of Global Terrorism—2003 (Washington, D.C.: Secretary of State and the Coordinator for Counterterrorism, U.S. State Department, Apr. 2004).
 Los Angeles Times, Sept. 12, 2004.
 "A Turning Point? George W. Bush, John Kerry and American Policy toward Iran," John R. Bolton, under secretary of state for arms control and international security, address to the Hudson Institute, Washington, D.C., Aug 17, 2004.
 9-11 Commission Report (Washington, D.C.: The National Commission on Terrorist Attacks upon the United States, July 22, 2004).
 The Washington Post. June 28, 1997.
 "The Foundation of the New Terrorism," 9-11 Commission Report, p. 60.
 Ibid., p. 61.
 "Al Qaeda Aims at the American Homeland," ibid., p. 169.
 Secretary of State Madeleine K. Albright, remarks before the American-Iranian Council, Mar. 17, 2000.
 The Christian Science Monitor, Apr. 19, 2004.
 "Progress Report on the Global War on Terrorism," White House, Sept. 2003.
 CNN.com, Sept. 17, 2002.
 "The Attack Looms," 9-11 Commission Report, pp. 240-1.