The bin Laden files proved to be a crucial source of intelligence. The documents and media were used to identify and hunt down al-Qaeda operatives, revise the U.S. government’s flawed model for understanding how the group works, and garner terrorist convictions in Western courts, among other uses. Iran is one of the subjects that is discussed with regularity in the files.

While bin Laden didn’t live inside Iran, many of his family members did. And during the last year of his life in Abbottabad, bin Laden worried repeatedly about their fate, especially his young son Hamza. Like other al-Qaeda men and women, Hamza fled to Iran after 9/11. Hamza was married while there, and his wedding video was among the files seized in Abbottabad. (In 2017, I helped convince the CIA to release Hamza’s wedding video to the public.) At times, Hamza and other al-Qaeda men enjoyed a loose house arrest inside Iran. But eventually the issue became contentious. Osama and his lieutenants discussed ways to force the Iranians to free a number of al-Qaeda operatives. At one point, they kidnapped an Iranian diplomat in order to force an exchange. Osama also instructed his right-hand man, Atiyah Abd al-Rahman, to be wary of bin Laden family members returning from Iran because they may be tracked. Rahman perished in the drone campaign months after bin Laden’s death. And Hamza was eventually tracked down as well.

The Abbottabad files also show that bin Laden was worried about Iran’s expanding influence throughout the Middle East and thought of ways to combat it. Al-Qaeda and Iran have been at odds in multiple ways, including during the wars in Iraq, Syria, and Yemen. Yet, duplicity is the name of the game. And al-Qaeda’s founder surmised that it was better to avoid a direct confrontation with the Iranians. When the head of the Islamic State of Iraq, an al-Qaeda-affiliated group, threatened to attack Iran in 2007, bin Laden sent a disapproving note.