1.6 Change in Power and Authority

Ali Khamenei, Iran's Supreme Leader since 1989, was killed in an airstrike on 28 February 2026, during a war between Iran and both Israel and the United States. In March 2026 the Assembly of Experts chose his son as the new Supreme Leader. It was only the second succession in the Islamic Republic's history. For the exam, the lesson is about rules, not personalities: the constitution gives the Assembly of Experts, an elected body of senior clerics, the job of choosing (and, in theory, dismissing) the Supreme Leader. Until it decides, a temporary council of top officials fills the role.

Many study guides and videos were made before this change, so check the date on anything you read about Iran.

Devolution is when a central government hands some powers to regional governments but keeps the legal right to take them back. After referendums in Scotland and Wales in 1997 and in Northern Ireland in 1998, the UK created the Scottish Parliament, the Welsh Assembly (renamed the Senedd in 2020) and the Northern Ireland Assembly. All three took up their powers in 1999. They make laws on matters like health and education. Scotland has since gained more powers, including over some taxes.

Decentralization more broadly means moving power away from the center. Mexico gave states more control over spending and services from the 1990s, and Nigeria has gone from 12 states in 1967 to 36 today, partly to give more groups their own state governments.

China: In 2018 the National People's Congress removed the two-term limit on the state presidency, so the party leader can keep holding all three top posts with no fixed end. The same amendment wrote Communist Party leadership into Article 1 of the constitution.

Russia: From 2000 the center reined in regional governors, grouping regions into federal districts overseen by presidential envoys. A 2020 package of amendments, approved in a nationwide vote, reset the presidential term count for the sitting president, gave the Russian constitution priority over international rulings and strengthened the president's role in removing judges.

Iran: The 1989 amendments abolished the post of prime minister, made the president head of government and let a cleric become Supreme Leader without being one of the most senior religious scholars.

A regime changes when its basic rules and institutions are replaced. That can happen gradually, as in Mexico's series of election reforms, or suddenly, through a revolution or coup, as in Iran in 1979.

Governments change more often and more easily: through elections, appointments or rules of succession, like a party choosing a new leader in the UK. Sometimes they fall by force. Nigeria had six successful military coups between 1966 and 1993.

Notice how each change was approved. UK devolution followed referendums in Scotland and Wales in 1997. Russia put its 2020 amendments to a nationwide vote. China's 2018 amendment passed the National People's Congress with only two votes against. The approval process can add legitimacy to a change, or reveal how little real opposition the system allows.