The United States is considering new military strikes against the Islamic Republic of Iran over its deadly crackdown on protests this month, Reuters reported.
The complexity of Iran's ruling system, the ideological nature of its support base and the strength of the Islamic Revolutionary Guard Corps make it difficult to predict its resilience or vulnerability to external attack or what might follow.
Here's how the system works and who the key figures are in Iran today:
Why does Iran have a "supreme leader"?
Iran's political system is based on the theory of wilayat-e faqih ("supremacy of the jurist") the jurist"), which argues that until the return of the Shiite Muslim 12th Imam, who disappeared in the ninth century, power in the land should be exercised by a supreme cleric.
The first Supreme Leader, Ayatollah Ruhollah Khomeini, was the charismatic father figure of the 1979 Islamic Revolution, who developed the model of a cleric standing above an elected government.
His successor, Ayatollah Ali Khamenei, has solidified this role since becoming leader in 1989. This ensures that he retains the final say on all major policy decisions and has built a parallel system of governance alongside that of the elected government, composed of loyalists.
Khamenei's influence is often exercised through the National Security Council, headed by longtime adviser Ali Larijani. Other advisers to Khamenei, including former Defense Minister Ali Shamkhani and former Foreign Minister Ali Akbar Velayati, have also played important roles.
The 86-year-old Khamenei has not named a successor, and it is unclear who would replace him if he were to be assassinated or removed from power.
His son, Mojtaba Khamenei, is sometimes considered a possible candidate. The grandson of his predecessor, Hassan Khomeini, is another, as are some older senior clerics.
Is Iran a theocracy?
Iran's clerical elite controls powerful bodies that extend their influence throughout the political system.
The Assembly of Experts, made up of senior ayatollahs elected every eight years, is the body that appoints the supreme leader. The constitution also gives it the power to question and even dismiss a leader, but it has never done so.
The Guardian Council - half appointed by the leader and half by the head of the judiciary - can veto laws passed by parliament and disqualify candidates in elections - a mandate used to block potential critics of Khamenei.
Another clerical body, the Expediency Council, appointed by Khamenei, resolves disputes between the elected parliament and the Guardian Council.
Iran follows Shiite interpretations of Islamic sharia law, and its judges are also clerics under the leadership of a head of the judiciary appointed by Khamenei. The current leader, Gholamhossein Mohseni Ejei, was sanctioned by Western countries for violent repression of protesters in 2009, when he was intelligence minister.
Other influential clerics include the head of the Expediency Council and former head of the judiciary, Sadiq Larijani, brother of Ali Larijani; the member of the Assembly of Experts and the Expediency Council, Mohsen Araki; and the leader of Friday prayers in Tehran, Ahmad Khatami.
However, not all clerics - even the senior ones - are necessarily supporters of Iran's theocratic system or its current rulers. Some were dissidents, others, like former President Mohammad Khatami, tried unsuccessfully to reform and soften the existing system. How powerful is the Revolutionary Guard? Unlike the regular military, which is subordinate to the Ministry of Defense in the elected government, the Islamic Revolutionary Guard Corps reports directly to the Supreme Leader. Formed soon after the revolution, the Islamic Revolutionary Guard Corps' role in defending the Islamic system expanded significantly during the 1980-88 war with Iraq, and it is now the strongest and best-equipped part of Iran's armed forces. Over the decades, the Guard has expanded its influence in the world of politics and business, gaining power at home and abroad. The "Quds" Force - an elite unit of the Guard, spearheaded Iran's regional strategy to support allied Shiite groups in the Middle East, most notably in Lebanon and Iraq. This strategy was severely affected by the US killing of Quds Force commander Qassem Soleimani in an airstrike in Iraq in 2020 and the defeat of the Lebanese group Hezbollah by Israel in the 2024 war.
The Basij militia, a part-time paramilitary force under the Guard's control, is often used to suppress protests in Iran.
Since the early 2000s, the Guard's economic power has grown as its contractor, Khatam al-Anbiya, has won billions of dollars in projects in Iran's oil and gas sector.
The targeted nature of Israeli strikes against senior Guard commanders last year and Hezbollah leaders in 2024 has raised questions about possible infiltration of the corps' upper echelons by Western intelligence.
However, Guard commander Mohammad Pakpour, his deputy Ahmad Vahidi, naval commander Alireza Tangsiri, and the current commander of the Quds Force Esmail Ghaani remain influential figures.
Is Iran also a democracy?
Iranians elect a president and parliament to four-year terms. The president appoints a cabinet that runs day-to-day politics within parameters authorized by the supreme leader.
In the early years of the Islamic Republic, voting attracted mass participation. But the Guardian Council’s restrictions on candidates and the highly contested 2009 election result eroded trust among many voters, and the overarching role of the supreme leader reduced the reach of electoral bodies.
President Massoud Pezeshkian, considered a moderate, was elected in 2024 after a first-round vote with about 40% turnout and a runoff in which about half of the electorate participated. He defeated Saeed Jalili, a Khamenei loyalist and anti-Western hardliner who remains influential.
The speaker of parliament since 2020 is former Guards commander Mohammad Baqer Qalibaf.