Who commits the attacks
The annex doesn’t sort attacks by sect, but it doesn’t need to. The identity of the top perpetrator groups tells the story on its own. Year after year across 2004–2023, the most active and lethal groups are Sunni: the Taliban, ISIS, Boko Haram, al-Qaeda and its affiliates, al-Shabaab, the TTP. On the order of nine in ten attacks in the reporting trace back to Sunni extremist actors operating out of the Salafi-jihadist tradition. None of them answer to Tehran. Most regard Shia Muslims — Iran very much included — as heretics, and target them accordingly. ISIS has spent years at open war with Iran and its allies.
A separate French dataset, compiled by FONDAPOL over a longer 1979–April 2024 window, lands in the same place. The five deadliest Islamist groups over that period account for better than 80 percent of all victims of Islamist terrorism — and every one of the five is Sunni: the Taliban, ISIS, Boko Haram, al-Shabaab, and al-Qaeda.
Where are the Iran-linked groups in all this? Largely absent from the top of the tables. Hezbollah and the Iran-aligned militias tend not to appear, in part because their operations are directed mainly at military forces rather than civilians, which places them outside the working definition of terrorism the reports use. The Houthis are the main Shia-linked group to surface in recent editions, and only as a small share of the total.