Unity and Power
Historically, theocracies have often succeeded in creating vast empires. The Egyptian, Mayan and Aztec empires all had theocratic governments. Although the Muslim world has not been unified under a single caliph or leader since the death of Muhammad in 632, many Muslims have acknowledged the spiritual and secular authority of powerful caliphs over the centuries. The fall of the last caliphate during the secularization of Turkey in 1924 has inspired several movements, including Hizb-ut Tahrir, dedicated to installing a single caliph as the ruler of all Muslim nations. Supporters of this movement see modern, secular states in the Muslim world as being the artificial creations of European colonial powers. They say a restored caliphate could unite all Muslim nations and protect them from being dominated or exploited by non-Muslim countries.
Social Reform
The concept of theocracy sometimes appeals to people who would like to see drastic social changes and reforms to bring the laws in line with their religious beliefs. The early followers of the Mormon church in the United States wished to institute the custom of plural marriage, but most non-Mormons were bitterly opposed to this practice. Mormon leaders held secular as well as religious authority in the territory of Utah, and they were able to write the laws to allow for plural marriage until Utah became a state. Many Muslims support movements like the Hizb-ut Tahrir or the Muslim Brotherhood because they believe that a government based on Islamic law would end the corruption and injustice they have experienced under secular regimes.
Authoritarianism and Intolerance
Theocratic governments tend to be authoritarian and intolerant of other belief systems. In the Islamic Republic of Iran, religious minorities such as the Baha'i faith have no legal recognition and members of sects other than Shi'ite Islam cannot run for president. Movements advocating a theocracy often arouse fierce opposition from people afraid of being governed by religious authorities, making it difficult for the movement to achieve its goals. For example, Egypt's Muslim Brotherhood has faced violent repression since its founding in 1928.
No Imitation, No Innovation
According to "The Political Economy of Theocracy" by Ronald Wintrobe and Mario Ferrero, theocracies suffer from a long-term disadvantage because of their own resistance to change. When a secular nation develops an important innovation in science or technology, other secular nations will quickly imitate it if they can. Theocracies may view the same idea with suspicion as the product of a society they see as corrupt. Over a long period, the theocratic nation will slip further behind its neighbors and become economically disadvantaged. Despite this tendency, Wintrobe and Ferrero note that theocracies have sometimes produced stable and long-lasting political structures. One example of a stable and influential modern theocracy is Vatican City, where the pope rules as head of state.