Iran’s Islamic revolutionary guard poised for more power

But the attacks are also increasing the chance of a change in leadership that would concentrate power in the hands of the elite military force, potentially resulting in a more hawkish and anti-Israeli Iran.

Recent Israeli strikes killed many senior Guard personnel, including its top commander and the architect of Iran’s ballistic-missile program. The Revolutionary Guard has responded with daily missile barrages over Tel Aviv, including at military sites and a hospital on Thursday, and warned the U.S. not to get involved.

The war has dealt the most severe blow to Iran in four decades, and thrust it into existential peril. Supreme Leader Ayatollah Ali Khamenei’s rule depends to a large extent on loyalty from the Guard. In turn, he has empowered the military force to the extent that it is likely to outlive the supreme leader. If Khamenei were toppled or killed, the Revolutionary Guard would most likely step in and dictate a new ruler—and in doing so, assume unprecedented power.

“The balance of power within Iran in the aftermath of this will shift in the direction of the military, in the direction of the Guard," said Ray Takeyh, an Iran expert and senior fellow with the Council on Foreign Relations. “Those in charge will be the men with guns. And they will try to bring back some sort of clerical leadership because, after all, this is an Islamic Republic."

Since its formation in 1979, the Islamic Revolutionary Guard Corps, or IRGC, has been the most powerful branch of Iran’s armed forces and is separate from—and more powerful than—the national army. It has its own ground forces, navy, air force, intelligence and special forces, totaling roughly 125,000 personnel. It is also deeply embedded in Iran’s economic system, political affairs and social fabric.

The Islamic Republic isn’t a one-man rule but a constellation of power centers coalescing under the supreme leader’s authority. In a fragmented country, the Revolutionary Guard has over time emerged as the single-most powerful actor, partly due to an expansive economic empire.

The U.S. has sought to curb the influence of the Guard by designating it a terrorist organization in 2019 and targeting it with economic sanctions. In 2020, during the first Trump presidency, a U.S. military strike killed Qassem Soleimani, the head of the Guard’s international Quds Force and its most prominent commander.

The Guard dominates all major infrastructure sectors, including oil and gas, construction and telecommunications. It trades in consumer goods and benefits from parastatal charities operating hundreds of subsidiaries in everything from agriculture to tourism.

“Millions of people depend on the economic empire of the Revolutionary Guard," said Ali Alfoneh, an expert on the IRGC at the Arab Gulf States Institute in Washington, D.C., and author of a book about the Guard.

In a sense, he said, Iran’s Revolutionary Guard is similar to the military in Egypt, which has dominated the state since 1952, or in Pakistan, where the armed forces have exerted control since 1947, including through three major coups.

While the Guard’s external operations have been severely hampered by Israel’s military campaign, its dominance at home hasn’t. If the supreme leader were toppled and foreign enemies sought to foment public unrest by bombarding the country, enforcing a no-fly zone and applying economic pressure—as they did against Saddam Hussein’s Iraq in the 1990s—the Guard would use brute force to maintain power, Alfoneh said.

“IRGC as an organization is capable of fighting a civil war, and prevailing in a civil war, against an opposition [potentially] financed and armed by Israel and the U.S.," he said.

While personalities matter in the Revolutionary Guard—its commanders advise the supreme leader—its leadership is mostly collective and to an extent informal, consisting of current and retired officers from different factions. Despite the recent deaths of senior commanders, the IRGC has remained cohesive enough to launch daily barrages of retaliatory missiles against Israel.

Formed after the revolution that toppled the U.S.-backed shah, the Revolutionary Guard’s initial purpose was to protect the nascent state against domestic and foreign threats, military as well as ideological. Many of its current commanders are veterans of Iran’s eight-year war with Iraq in the 1980s, one of the deadliest global conflicts of the past century.

The war, in which Saddam Hussein’s regime, backed by the U.S., killed hundreds of thousands of Iranians including with chemical weapons, still shapes the Guard’s outlook on its neighbors and the West, and forms a cornerstone of its religious-nationalist doctrine.

To build allegiance, the IRGC formed local community networks, primarily through the Basij, a paramilitary group best known in the West for violently oppressing demonstrations, but which also engages in political and social activities.

The Basij engages with Iranians across the country, from kindergarten to adulthood. It offers religious and ideological teachings and after-school activities. It sponsors sporting events like weightlifting, wrestling and taekwondo. Members can buy groceries at a discount.

“The main reason the Basij has been able to attract people in the past is that it gives poor kids a thing to do," said Afshon Ostovar, associate professor at the Naval Postgraduate School in Monterey, Calif., and author of a book on the IRGC. “At its lowest ranks it’s the Cub Scouts. You do arts and crafts, and sing songs. It’s a patriotic sort of movement," he said. “But once you get to high-school ranks, they start to take from the Basij people who can be useful in security work."

A military parade in Tehran in January featured members of the Basij paramilitary force.

If the IRGC were forced to consolidate a new rule, the Basij would be crucial in maintaining internal security, Ostovar said.

Wholesale regime change that dislodges the Revolutionary Guard completely wouldn’t just bring about political change, but also tear apart the social fabric in parts of Iranian society. Yet, as is often the case in regime changes, many economic structures and enterprises would likely survive, including those of the IRGC, said Esfandyar Batmanghelidj, founder and CEO of the Bourse and Bazaar Foundation, an economic think tank.

“The individuals and networks who make up the IRGC are embedded in state institutions and in economic entities, commercial entities, to an extent where I think there would remain a lot of continuity, even if there were a big political transition," Batmanghelidj said. “And that’s something I rarely see people grappling with."

No matter the outcome of the current war with Israel, the Islamic Republic faces a historic reckoning. Many Iranians will blame the leadership, and particularly the Revolutionary Guard, for dragging the country into a devastating war. Its economic dominance is also a source of anger among Iranians fed up with economic hardship at a time when some Guard members have benefited from sanctions evasion.

“This is a paramilitary force that engages in plenty of corruption, and its whole raison d’être was to defend the state," Takeyh said.

The IRGC has its own ground forces, navy, air force, intelligence and special forces, totaling roughly 125,000 personnel.

The Guard also faces a reckoning within its own ranks, where some argue that a more militant approach to Iran’s enemies could have staved off the current war. Over the past year, some IRGC officials in the group’s own publications have advocated for weaponizing the country’s nuclear program.

Younger veterans of Iran’s recent military ventures in Iraq, Syria, Lebanon and Yemen who have helped Iran grow into a regional powerhouse may blame their leaders for not dealing a decisive blow to its enemies and allowing the war to come to Iran, Ostovar said. Assassinating Khamenei could stoke such fervor, he added.

“You could have a military coup that instead of bringing forth a more liberal, secular, normal regime could actually bring forward a much more aggressive, hawkish, reactive, reactionary regime," he said.

Write to Sune Engel Rasmussen at sune.rasmussen@wsj.com