The Salafi-Jihadi movement synthesizes Salafi/Wahhabi theology with the political revolutionary theory of Sayyid Qutb (Muslim Brotherhood). Key figures: Abdullah Azzam (1941–1989 AD), the Palestinian scholar who mobilized international volunteers for the Afghan jihad against the Soviets and whose writings define the modern concept of offensive jihad as individual obligation (fard ayn); Osama bin Laden (1957–2011 AD), his student, who turned the jihadist network against the United States; Ayman al-Zawahiri; and Abu Musab al-Zarqawi. The movement produced al-Qaeda (founded 1988), the Iraqi insurgency, and ISIS/ISIL (Islamic State, 2013). ISIS explicitly claims to replicate the earliest Islamic caliphate, enforcing a strict Salafi interpretation of sharia. The Salafi-Jihadi movement represents a tiny fraction of Muslim opinion globally but has had an outsized impact on world history and on Western perceptions of Islam.