The Constitution of the Islamic Republic of Iran is based on the concept of velayat-e faqih (Guardianship of the Islamic Jurist), which grants a learned Islamic jurist (faqih) – a cleric tasked with interpretation of sharia (divine Islamic law) – with the role of Supreme Leader. The Supreme Leader of Iran holds final religious and political authority over all affairs of the state, ruling essentially by divine right. Velayat-e faqih, as practiced in Iran, is a modern innovation in Shi’a religious doctrine based on the ideology of Ayatollah Ruhollah Khomeini, the founder of the Islamic Republic. For centuries before, Shi’a Muslims traditionally adhered to a limited interpretation of velayat-e faqih, in which the clergy was responsible for the interpretation and administration of religious law, while governance was the realm of secular authorities.

In 1970, Khomeini published his book, Islamic Government, advocating for an absolute version of velayat-e faqih. According to Khomeini’s vision, the Shi’a clergy (ulama) would oversee the creation and rule over an Islamic state in Iran, expanding the purview of the ulama’s role into the traditionally secular realm of governance. Khomeini built on the works of contemporary Sunni Islamist thinkers, such as Sayyid Qutb and Abul A’la Maududi, whose theocratic form of government served as a model for the Islamic Republic, and he was influenced by modern conceptions of nation-state power. He postulated that the state should be governed by sharia, and as the clergy had the greatest understanding of Islamic law, they should naturally be the guardians of state power until the return of the mahdi, or the Hidden Imam, a messianic Shi’a figure. Before Khomeini, Shi’a clergy typically advocated for quietism when it came to politics, refraining from engaging in politics or attempting to establish Islamic governance. In the traditional quietist view, because human beings are imperfect and fallible, they are thus considered incapable of establishing true, just Islamic rule in the absence of the mahdi. Khomeini broke from this tradition, arguing that rule by clerics was justified and necessary to preserve Islam until the mahdi’s return.     

While Khomeini borrowed from established theories of Islamic government, he also developed his own unique ideas and interpretations of Shi’a Islam. For instance, Khomeini called for a singular leading faqih, chosen from among those who have attained the highest status among the Shi’a clergy as a recognized marja e-taghlid (source of emulation), to be chosen to serve as the highest Islamic jurist (velayat-e faqih) with authority for the final say over all state and religious matters. Under Twelver Shi’ism, the dominant form of Islam practiced in Iran, a marja e-taghlid is a cleric holding the highest rank of Grand Ayatollah or Imam, who presides over a hawza (religious seminary) and makes decisions regarding the interpretation and practice of sharia, which is adhered to by the followers and lower-ranking clergy of their respective hawzas. Marjas serve as representatives of the mahdi on Earth and are responsible for setting and defining the parameters of Islamic jurisprudence. In Khomeinism, the designated marja as the velayat-e faqih would further draw upon their connection to the divine to steer the ship of state, exercising earthly authority as a deputy of the Hidden Imam.

Shortly after the 1979 Iranian Revolution, Iran conducted a popular referendum, where 97 percent of voters purportedly supported the establishment of an Islamic Republic. It is important to note that the draft constitution presented before the referendum did not explicitly mention Khomeini’s ideas of Islamic governance or velayat-e faqih. Therefore, those who participated in the vote (although some Marxist and Kurdish factions boycotted it, the participation was nearly universal) may not have necessarily intended to endorse a theocratic autocracy but rather to support a form of secular governance with a traditional head of state and Islam as the foundation for the legal system. While still in exile in Paris in September 1978, he said, “Our intention is not that religious leaders should themselves administer the state, but that they should guide the people in determining what the demands of Islam are."

After the referendum, Khomeini retracted his support for the original secular draft constitution and advocated for establishing a system based on velayat-e faqih. Khomeini strategically worked to populate the newly formed Assembly of Experts for Constitution, responsible for crafting the first official constitution of the newly established Islamic Republic of Iran, with individuals loyal to him. This ensured that the authoritative role of a marja e-taghlid serving as the velayat-e faqih was codified into law and that his own designation as Iran’s Supreme Leader was an accomplished fact.

Khomeini’s bait-and-switch maneuver ensured that the popular Iranian Revolution transformed into an  Islamic Revolution, discarding the aspirations of non-Islamist partners within the broad-based anti-Shah coalition. These temporary allies, who had rallied around Khomeini, perceived him as a symbolic leader and spiritual guide for the revolution but failed to comprehend the extent of his ambitions to rule Iran. As Khomeini and his acolytes set about consolidating their power, they executed hundreds of former regime agents and leftists, communists, secularists, Kurds, and other opposition elements within the anti-Shah coalition.

Khomeini swiftly implemented his vision of sharia, emphasizing “purifying” society and the body politic from perceived Western political and cultural influences. This included imposing bans on music and alcohol, enforcing laws mandating the veiling of women, instituting harsh penalties, including execution for crimes of sexual immorality such as adultery and homosexuality, and an aversion to cultural, educational, or economic engagement with the West.

Enmity toward the West, particularly the United States, still frequently referred to as the “Great Satan,” and the export of the revolution are defining principles of Khomeinism, in addition, to velayat-e faqih. Iran has framed its Islamic Revolution as a supranational liberation movement of oppressed Muslims from “arrogant” colonialist powers who seek to subjugate Islam. Article 152 of Iran’s constitution speaks of the country’s foreign policy being based on “the defense of the rights of all Muslims.” Article 154 explicitly states that the Islamic Republic “supports the just struggles of the mustad'afun [oppressed] against the mustakbirun [tyrants] in every corner of the globe.” Thus, the Islamic Republic’s aspiration to lead a global movement is built into its DNA.

In practice, this means that the Supreme Leader is not just the leader of Iran but also of all Muslims who subscribe to the Khomeinist notion of velayat-e faqih. Iran has backed Shi’a terror movements and militias, most notably Hezbollah, throughout the region that adhere to this doctrine and, thus, prioritize loyalty to Iran’s Supreme Leader over loyalty to their own nation. Iran has also established a worldwide network of religious and cultural institutions to cultivate pockets of loyalists to the Islamic Revolution and the Supreme Leader in countries around the globe as part of its long-term project to spread the Islamic Revolution.

Within Iran, the Supreme Leader is the most powerful figure in the country and controls all organs of state and religious power. The Iranian constitution sought to create a hybrid governing system with theocratic authoritarian and republican elements; however, the system is designed so that the republican elements are always subordinate to the will of the Supreme Leader. While Iran has an elected executive (president) with authority to appoint several key cabinet officials, a representative legislative body (majles), and a judiciary, these republican elements all operate under the oversight of the Supreme Leader. The republican elements are responsible for managing the day-to-day affairs of the government, but the Supreme Leader supervises their performance to ensure that all decisions align with Khomeinist principles and the Islamic Revolution.

At the time of the Islamic Revolution, Khomeini insisted that a clerical Supreme Leader was not inconsistent with democracy, claiming, “Since the people love the clergy, have faith in the clergy, want to be guided by the clergy, it is right that the supreme religious authority should oversee the work of the Prime Minister or of the President of the republic, to make sure that they don't make mistakes or go against the law: that is, against the Koran.” Due in part to both design and circumstances, over the years, the Supreme Leader’s power has grown relative to the republican elements of Iran’s revolutionary system. Instead of solely providing oversight and ensuring that all functions of statecraft comply with sharia, in practice, the Supreme Leader possesses final decision-making powers over Iran’s foreign and domestic policies.

Underscoring the Supreme Leader’s dominance is the fact that he even has authority over who can serve in Iran’s quasi-elected positions through the Guardian Council, a 12-member deliberative body with six members directly appointed by the Supreme Leader and the other six approved by the majles from a list of candidates put forward by the head of Iran’s judiciary. The Supreme Leader appoints the head of the judiciary, so he enjoys total control over the Guardian Council, which approves candidates for office and reviews all laws to ensure their compliance with sharia. As a result, no candidate can run for office, and no law can be passed without the consent of the Supreme Leader.

Given the Supreme Leader’s status as a deputy of the Divine, there are essentially no earthly checks on his power. An 88-member body called the Assembly of Experts, composed of Islamic legal scholars, is responsible for appointing the Supreme Leader in the event of a vacancy. It is also constitutionally mandated with authority to dismiss the Supreme Leader if he becomes incapable of fulfilling his constitutional duties or if it is found that he did not possess the proper qualifications for the role initially. The Assembly of Experts is theoretically supposed to monitor the Supreme Leader's activities, but there are no formal channels under Iran’s constitution through which the Assembly can critique or challenge the Supreme Leader. Since 1991, the Guardian Council has assumed a supervisory role over the Assembly. The Guardian Council ensures that candidates meet the conservative-dominated Council’s vetting standards effectively gaining approval from the Supreme Leader and becoming subject to his veto power as well. This has further eroded any potential oversight role that the Assembly may have had.

The Supreme Leader holds numerous other roles that serve to underscore his absolute authority within Iran. He has the power to appoint and to dismiss the heads of various critical institutions essential to the functioning of the state, ensuring his control over key centers of power, including the judiciary, military, domestic law enforcement, intelligence agencies, and the media. As the commander-in-chief of all armed forces, he appoints their leadership, including both the conventional military and the regime’s praetorian guard, the Islamic Revolutionary Guard Corps (IRGC), which is responsible for preserving and spreading the Islamic Revolution at home and abroad. The Supreme Leader also oversees and has significant influence over Iran’s intelligence agencies, ensuring they serve his foreign and domestic policy imperatives. This control grants him a potent tool for monitoring and repressing Iran’s citizenry and dissidents abroad, as well as for facilitating terrorist activities beyond Iran’s borders.

Furtherore, the Supreme Leader also effectively controls Iran’s state-owned media apparatus, the Islamic Republic of Iran Broadcasting (IRIB). This umbrella organization is constitutionally mandated to be the sole legal TV and radio broadcaster in Iran. The Supreme Leader has the authority to select the head of IRIB, ensuring that regime loyalists have control over all legally disseminated broadcast media in Iran. The IRIB’s mission is to consistently deliver messaging that supports the regime’s domestic, foreign policy, and military goals. Its programming aims to strengthen moral and religious values within Iranian society, uphold the revolutionary ethos of Iran, and to provide viewers with a theoretical foundation for Khomeinist principles, including velayat-e faqih. Thus, the IRIB plays a vital role in the Supreme Leader and revolutionary regime’s maintenance of cultural and political hegemony within Iranian society.

The power of the Supreme Leader is further bolstered by his control over a significant financial empire, which operates as a parallel economy to that of the Iranian state. Iran has a system of religious endowments, also known as bonyads, that hold billions of dollars in financial assets. The bonyad system was established shortly after the Islamic Revolution by Ayatollah Khomeini’s decree. The “seed money” for these endowments came from property and assets seized from the Shah of Iran, the royal family, as well as confiscated properties from religious minorities, dissidents, and others who fled Iran. The bonyads function as both profit-making conglomerates, operating hundreds of companies engaged in trade and commerce in fields such as automobile manufacturing, infrastructure, construction, financial services, and oil and gas. They also serve as charitable and cultural institutions that provide social services to the poor, orphans, wounded veterans, and families of martyrs, while promoting the regime’s religious and political ideology. Furthermore, there are allegations that some bonyads channel funds to Hezbollah and other regional terrorist groups, fueling terrorism and sectarian conflicts in the region to advance Iranian foreign policy objectives.

Because Iran primarily relies on oil revenues for the majority of its discretionary budget, the bonyads are able to operate in an opaque manner, without being subjected to public transparency or government audits, and are fully exempt from taxation. At the same time, the bonyads are reportedly allocated roughly half of the state’s budget and frequently secure government contracts. Although they serve as conduits for corruption and their substantial resources impede competition from more efficient private-sector businesses, the bonyads are a vital pillar of the Supreme Leader’s political survival.

They provide him with an independent means of dispensing patronage to clerical and military elites, who are granted autonomous operation over individual bonyads. This autonomy allows them to amass large profits, ensuring their loyalty to the Supreme Leader. Moreover, the bonyads contribute to fostering dependence among impoverished Iranians on their financial assistance, thereby strengthening their support for the ruling regime. However, in recent years, the bonyads have served as a locus of protests and civil unrest. Since December 2017, Iran has witnessed a renewed protest movement critical of the regime’s economic mismanagement and corruption driven in part by anger over increased government spending on bonyads and religious institutions at a time of increased privation, unemployment, and inflation for ordinary Iranians.