Ottoman Empire
Several historians such as British historian Edward Gibbon and the Greek historian Dimitri Kitzikis have argued that after the fall of Constantinople, the Ottoman state took over the machinery of the Roman state, and that in essence the Ottoman Empire was a continuation of the Eastern Roman Empire under a thin Turkish Islamic guise. Kitzikis called the Ottoman state "a Greek-Turkish condominium". The American historian Speros Vryonis wrote that the Ottoman state was centered on "a Byzantine-Balkan base with a veneer of the Turkish language and the Islamic religion". Other historians have followed the lead of the Austrian historian Paul Wittek who emphasized the Islamic character of the Ottoman state, seeing the Ottoman state as a "Jihad state" dedicated to expanding the world of Islam. Another group of historians led by the Turkish historian M. Fuat Koprulu championed the ""gazi" thesis" that saw the Ottoman state as a continuation of the way of life of the nomadic Turkic tribes who had come from East Asia to Anatolia via Central Asia and the Middle East on a much larger scale, and argued that the most important cultural influences on the Ottoman state came from Persia. More recently, the American historian Heath Lowry called the Ottoman state a "predatory confederacy" led in equal parts by Turks and Greeks converted to Islam.
Sunni Islam
The fall of the Ottoman, the biggest Sunni empire in the world for six centuries, the mightiest power in the Mediterranean world and one of the important participants in World War I which joined the war on the side of the Central Powers, bringing caliphate to an end was an epochal event. This resulted in Sunni protests in far off places including the Khilafat Movement in India, which was later on upon gaining independence from Britain divided into Sunni dominated Pakistan and secular India. Pakistan, the most populous Sunni state at its birth, however later got partitioned into Pakistan and Bangladesh. The demise of Ottoman caliphate also resulted in the emergence of Saudi Arabia, a dynastic absolute monarchy with the support of the British and Muhammad ibn Abd al-Wahhab, the founder of Wahhabism. This was followed by a considerable rise in Wahhabism, Salafism and Jihadism under the influence of the preaching of Ibn Taymiyyah a follower of Ahmad bin Hanbal.The expediencies of cold war resulted in encouragement of Afghan refugees in Pakistan to be radicalised, trained and armed to fight the communist regime backed by USSR forces in Afghanistan giving birth to Taliban. The Taliban wrestled power from the communists in Afghanistan and formed a government under the leadership of Mohammed Omar, who was addressed as the Emir of the faithful, an honorific way of addressing the caliph. The Taliban regime was recognised by Pakistan and Saudi Arabia till after 9/11 perpetrated by Osama bin Laden a Saudi national by birth harboured by the Taliban took place, resulting in a war on terror launched against the Taliban.