The previously unseen document, which was released along with 470,000 files recovered in the raid on Osama Bin Laden’s Abbottabad compound in Pakistan in May of 2011. The newly-available material provides invaluable insights into the terrorist organization that struck America on September 11, 2001.

The Long War Journal, which chronicles the U.S. war on terror, and has advocated for the release of bin Laden’s secret cache since 2011, arguing that such transparency would help to better inform the American people, experts and policymakers. Translations by the Long War Journal have shown how Iran offered the ‘Saudi brothers’ in al-Qaeda “everything they needed” if they were to carry out strikes on U.S. interests in Saudi Arabia and the Gulf. This extended to “money, arms” and “training in Hezbollah camps in Lebanon”, the documents reveal.

Those who have seen the documents say they provided logistical assistance to al-Qaeda, which facilitated travel for operatives, and provided safe houses for others. Tehran provided safe-haven for prominent ideologue Abu Hafs al-Mauritani and his followers in Iran, prior to the 9/11 attacks.

Callum Paton, staff writer at Newsweek specializing in North Africa and the Middle East, says in an article that, “Relations were often fractious between the Sunni al-Qaeda and Shiite Iran, even if both recognized they were never in open war that their ‘interests intersect’ on the issue of their shared classification as an ‘enemy of America’.” He adds, “At one point Al-Qaeda contacted Ayatollah Khamenei directly, demanding the release of prisoners in Iranian custody.”

Previously released files show that Bin Laden cautioned against being overly antagonistic towards Iran which he described as al-Qaeda’s “main artery for funds, personnel and communication.”

C.I.A. Director Mike Pompeo said last month at the Foundation for the Defense of Democracies in Washington, “It’s an open secret and not classified information that there have been relationships, there are connections. There have been times the Iranians have worked alongside al-Qaeda.” Pompeo added that the relationships between al-Qaeda and Iran, as outlined in the documents released by the C.I.A., will continue be under close surveillance.