Once the subject of intense conflict and rivalry amongst Muslim rulers, the caliphate has lain dormant and largely unclaimed since the 1920s. For some ordinary Muslims the caliph as leader of the community of believers, "is cherished both as memory and ideal" as a time when Muslims "enjoyed scientific and military superiority globally,"[36] though "not an urgent concern" compared to issues such as the Israeli-Palestinian conflict.

Tight restrictions on political activity in many Muslim countries, coupled with the obstacles to uniting over 50 nation-states under a single institution and a lack of interest from all Muslims apart from some groups (like Hizb ut-Tahrir), have ensured that calls to revive the Caliphate have remained muted. Popular apolitical Islamic movements such as the Tablighi Jamaat identify a lack of spirituality and decline in personal religious observance as the root cause of the Muslim world's problems, and claim that the caliphate cannot be successfully revived until these deficiencies are addressed. No attempts at rebuilding a power structure based on Islam were successful anywhere in the Muslim world until the Iranian Revolution in 1979, which was based on Shia principles and whose leaders did not outwardly call for the restoration of a pan-Islamic Caliphate.

Islamist call

A number of Islamist political parties and Islamist guerrilla groups have called for the restoration of the caliphate by uniting Muslim nations, either through political action (e.g., Hizb ut-Tahrir) or through force (e.g., al-Qaeda). Various Islamist movements have gained momentum in recent years with the ultimate aim of establishing a Caliphate; however, they differ in their methodology and approach. Some are locally-oriented, mainstream political parties that have no apparent transnational objectives.

Khilafa means representative. Man, according to Islam is the representative of "people", His (God's) viceregent; that is to say, by virtue of the powers delegated to him, and within the limits prescribed by the Qu'ran and the teaching of the prophet, the caliph is required to exercise Divine authority.

The Muslim Brotherhood advocates pan-Islamic unity and implementing Islamic law, it is the largest and most influential Islamic group in the world, and its offshoots form the largest opposition parties in most Arab governments.[39] Founder Hassan al-Banna wrote about the restoration of the Caliphate.

One of clearly stated goals of the radical Islamist group al-Qaeda's is the re-establishment of a caliphate.[41] Bin Laden has called for Muslims to "establish the righteous caliphate of our umma." Al Qaeda recently named its Internet newscast from Iraq "The Voice of the Caliphate."

According to author Lawrence Wright, Ayman al-Zawahiri, an active member of the Muslim Brotherhood, "sought to restore the caliphate, the rule of Islamic clerics, which had formally ended in 1924 following the dissolution of the Ottoman Empire but which had not exercised real power since the thirteenth century. Once caliphate was established, Zawahiri believed, Egypt would become a rallying point for the rest of the Islamic world, leading the jihad against the West. "Then history would make a new turn, God willing," Zawahiri later wrote, "in the opposite direction against the empire of the United States and the world’s Jewish government."

One transnational group whose ideology is based specifically on restoring the caliphate as a pan-Islamic state, is Hizb ut-Tahrir (literally: "party of liberation"). It is particularly strong in Central Asia, Europe and growing in strength in the Arab world and is based on the claim that Muslim can prove that God exists[45] and that the Qur'an is the word of God. Hizb-Ut-Tahrir stated strategy is a non-violent political and intellectual struggle.

Opposition

Scholar Olivier Roy writes that "early on, Islamists replace the concept of the caliphate ... with that of the amir." There were a number of reasons including "that according to the classical authors, a caliph must be a member of the tribe of the Prophet (the Quraysh) ... moreover, caliphs ruled societies that the Islamists do not consider to have been Islamic (the Ottoman Empire)." (This is not the view of all Islamist groups, as both the Muslim Brotherhood (the largest) and Hizb ut-Tahrir view the Ottoman state as a caliphate.)

United States President George W. Bush has mentioned the Caliphate in speeches on the War on Terrorism claiming it as an integral part of the radical Islamic ideology at war with Western freedom.