International propagation of the Salafi movement and Wahhabism by region

Following the embargo by Arab oil exporters during the Arab–Israeli October 1973 War and the vast increase in petroleum export revenue that followed, the international propagation of Salafism and Wahhabism within Sunni Islam and throughout the Muslim world, favored by the conservative oil-exporting Kingdom of Saudi Arabia and other Gulf monarchies, achieved a "preeminent position of strength in the global expression of Islam." The Saudi interpretation of Islam not only includes Salafism and Wahhabism but also Islamist and revivalist interpretations of Islam, and a "hybrid" of the two interpretations (until 1990s).

From 1982 to 2005 the Saudi government, in an effort to spread the Salafi-Wahhabi brand of Islam across the world (dawah Salafiyya), spent over $75 billion via international organizations affiliated with the House of Saud and religious attaches at dozens of Saudi embassies, to establish/build 200 Islamic colleges, 210 Islamic centers, 1,500 mosques, and 2,000 schools for Muslim children in Muslim-majority countries and elsewhere. Mosque funding was combined with persuasion to propagate the dawah Salafiyya; schools were "fundamentalist" in outlook and formed a network "from Sudan to northern Pakistan". Supporting proselytizing or preaching of Islam has been called "a religious requirement" for Saudi rulers that cannot [or could not] be abandoned "without losing their domestic legitimacy" as protectors and propagators of Islam.

Other strict and conservative interpretations of Sunni Islam assisted by funding from the Gulf monarchies include the Muslim Brotherhood and Jamaat-e-Islami (until the break between the Muslim Brotherhood and Gulf monarchies in the 1990s). While their alliances were not always permanent, they were said to have formed a "joint venture", sharing a strong "revulsion" against Western influences, a belief in strict implementation of Islamic law (sharīʿa), an opposition to both Shia Muslims and popular Islamic religious practices (the veneration of Muslim saints and visitations of their tombs), and a belief in the importance of armed jihad. A "fusion", or "hybrid", of the two movements came out of the Afghan jihad, where thousands of Muslims were trained and equipped to fight against Soviets and their Afghan allies in Afghanistan in the 1980s.

The funding has been criticized for promoting an intolerant, fanatical form of Islam that several political scientists and scholars of international relations consider to be the core cause of Islamic extremism and religiously-motivated terrorism worldwide, along with the Islamist ideology and practice of excommunication (takfīr). Critics argue that volunteers mobilized to fight in Afghanistan (such as Osama bin Laden) went on to wage jihad against Muslim governments and civilians in other countries, and that conservative Sunni groups such as the Taliban in Afghanistan and Pakistan are attacking and killing not only Non-Muslims (Kūffar) but also fellow Muslims they consider to be apostates, such as Shia Muslims and Sufi ascetics. As of 2017, changes to Saudi religious policy have led some to suggest that "Islamists throughout the world will have to follow suit or risk winding up on the wrong side of orthodoxy".