Pan-Islamism (Arabic: الوحدة الإسلامية) is a political movement advocating the unity of Muslims under one Islamic state – often a Caliphate – or an international organization with Islamic principles. As a form of internationalism and anti-nationalism, Pan-Islamism differentiates itself from pan-nationalistic ideologies, for example Pan-Arabism, by seeing the ummah (Islamic community) as the focus of allegiance and mobilization, excluding ethnicity as primary factors towards unification.
The model pan-Islamism aims for is the early years of Islam – the reign of Muhammad and the early caliphate – when the Muslim world was thought to be strong and uncorrupted in one united state.
In the modern era, Pan-Islamism was championed by Jamal al-Din al-Afghani who sought unity among Muslims to resist colonial occupation of Muslim lands. Afghani feared that nationalism would divide the Muslim world and believed that Muslim unity was more important than ethnic identity. Although sometimes described as "liberal", al-Afghani did not advocate constitutional government but simply envisioned “the overthrow of individual rulers who were lax or subservient to foreigners, and their replacement by strong and patriotic men.” In a review of the theoretical articles of his Paris-base newspaper there was nothing "favoring political democracy or parliamentarianism,” according to his biographer.
Pan-Islamism in the post-colonial world was strongly associated with Islamism. Leading Islamists such as Sayyid Qutb, Abul Ala Maududi, and Ayatollah Khomeini all stressed their belief that a return to traditional Sharia law would make Islam united and strong again. (Extremism within Islam goes back to the 7th century to the Kharijites. From their essentially political position, they developed extreme doctrines that set them apart from both mainstream Sunni and Shiʿa Muslims. The Kharijites were particularly noted for adopting a radical approach to Takfir, whereby they declared other Muslims to be unbelievers and therefore deemed them worthy of death.)