Iran’s Islamic Revolution in 1979 gave Shia cleric Ayatollah Ruhollah Khomeini the opportunity to implement his vision for an Islamic government ruled by the “guardianship of the jurist” (velayat-e faqih), a controversial concept among Shia scholars that is opposed by Sunnis, who have historically differentiated between political leadership and religious scholarship. Shia ayatollahs have always been the guardians of the faith. Khomeini argued that clerics had to rule to properly perform their function: implementing Islam as God intended, through the mandate of the Shia Imams.
Under Khomeini, Iran began an experiment in Islamic rule. Khomeini tried to inspire further Islamic revival, preaching Muslim unity, but supported groups in Lebanon, Iraq, Afghanistan, Bahrain, and Pakistan that had specific Shia agendas. Sunni Islamists, such as the Muslim Brotherhood and Hamas, admired Khomeini’s success, but did not accept his leadership, underscoring the depth of sectarian suspicions.
Saudi Arabia has a sizable Shia minority of roughly 10 percent, and millions of adherents of a puritanical brand of Sunni Islam known as Wahhabism (an offshoot of the Sunni Hanbali school) that is antagonistic to Shia Islam. The transformation of Iran into an overtly Shia power after the Islamic revolution induced Saudi Arabia to accelerate the propagation of Wahhabism, as both countries revived a centuries-old sectarian rivalry over the true interpretation of Islam. Many of the groups responsible for sectarian violence that has occurred in the region and across the Muslim world since 1979 can be traced to Saudi and Iranian sources.
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