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 similar to a European Union with Islamic principles. As a form of religious nationalism, Pan-Islamism differentiates itself from other pan-nationalistic ideologies, for example Pan-Arabism, by excluding culture and ethnicity as primary factors towards unification.
The concept of mujahideen volunteer Islamist fighters is closely related to pan-Islamic thought. Mujahideen may come from all over the Islamic world to assist in a conflict that they deem to be religiously important.
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. 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.
While Afghani's interest in Islamic law and theology was scant, later 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.
In the period of decolonialism following World War II, Arab nationalism overshadowed Islamism. In the Arab world secular pan-Arab parties – Baath and Nasserist parties – had offshoots in almost every Arab country, and took power in Egypt, Libya, Iraq and Syria. Islamists suffered severe repression; its major thinker Sayyid Qutb, was imprisoned, underwent torture and was later executed.
Following the defeat of Arab armies in the Six-Day War, Islamism and Pan-Islam began to reverse their relative position of popularity with nationalism and pan-Arabism. In 1979 the Iranian Revolution ousted Shah Mohammad Reza Pahlavi from power, and ten years later the Afghan Muslim mujahideen, with major support from the United States, successfully forced the Soviet Union from Afghanistan.
These events galvanised Islamists the world over and heightened their popularity with the Muslim public. Throughout the Middle-East, and in particular Egypt, the various branches of the Muslim Brotherhood have significantly challenged the secular nationalist or monarchical Muslim governments.
In Pakistan the Jamaat-e-Islami enjoyed popular support especially since the formation of the MMA, and in Algeria the FIS was expected to win the cancelled elections in 1992. Since the collapse of the Soviet Union, Hizb-ut-Tahrir has emerged as a Pan-Islamist force in Central Asia and in the last five years has developed some support from the Arab world.
Most recent advocate for Pan-Islamism was late Turkish prime minister and founder of Milli Gorus movement Necmettin Erbakan, who championed the Pan-Islamic Union (Islam Birligi) idea and took steps in his government toward that goal by establishing the Developing 8 Countries (or D8, as opposed to G8) in 1996 with Turkey, Egypt, Iran, Pakistan, Indonesia, Malaysia, Nigeria and Bangladesh. His vision was gradual unity of Muslim nations through economic and technologic collaboration similar to the EU with a single monetary unit (Islam Dinari), joint aerospace and defense projects, petrochemical technology development, regional civil aviation network and a gradual agreement to democratic values. Although the organization met at presidential and cabinet levels and moderate collaboration projects continue to date, the momentum was instantly lost when the so-called Post-Modern Coup of February 28, 1997, eventually took down Erbakan government.
- Bissenove (February 2004). "Ottomanism, Pan-Islamism, and the Caliphate; Discourse at the Turn of the 20th Century". BARQIYYA 9 (1) (American University in Cairo: The Middle East Studies Program). Retrieved April 26, 2013.
- such as by a contemporary English admirer, Wilfrid Scawen Blunt, (see: Wilfrid Scawen Blunt, Secret History of the English Occupation of Egypt (London: Unwin, 1907), p. 100.)
- Nikki R. Keddie, Sayyid Jamal ad-Din “al-Afghani”: A Political Biography (Berkeley: University of California Press, 1972), pp. 225-26.
- Faith and Power by Edward Mortimer Vintage; Vintage Books, 1982
- Hizb-ut-Tahrir's Growing Appeal in the Arab World Jamestown Foundation
-  Erbakan currency
-  D8 History
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- Nazir Ahmad Khan Chaudri. Commonwealth of Muslim States: a plea for Pan-Islamism, al-Ahibba (Friends of the Muslim World Muhibban-e-Alam-e-Islami), 1972.
- M. Naeem Qureshi. Pan-Islam in British Indian Politics: A Study of the Khilafat Movement, 1918-1924, Brill Academic Publishers, 1999, ISBN 90-04-10214-0.
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- Trifkovic, Serge (2006). Defeating Jihad. Regina Orthodox Press, USA. ISBN 1-928653-26-X.
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- Phillips, Melanie (2006). Londonistan: How Britain is Creating a Terror State Within. Encounter books. ISBN 1-59403-144-4.
- David Samuel Margoliouth (1922). "Pan-Islamism". Encyclopædia Britannica (12th ed.).
- Pan-Islamism in Oxford Islamic Studies Online
- al-Afghani's Vision of a Pan-Islamic Civilization
- al-Afghani Bibliography
- The Manchester Document