As Iran and Israel inch ever closer to a full-scale war, the Islamic Republic’s huge ballistic missile attack on Tel Aviv on October 1 may come to be seen as a decisive turning point. After successive setbacks for Tehran, including Israel’s assassination of the Hezbollah leader Hassan Nasrallah, Iranian Supreme Leader Ali Khamenei was left with little choice but to respond. Now, the region is staring down an even bigger conflict.

Although some kind of Iranian attack was inevitable, given how closely allied Hezbollah is to the Islamic Republic, Khamenei surprised many observers by taking one of the most extreme options. He could have used his network of proxies to launch an indirect attack against Israel or set off a wave of regional terrorism. Both are steps he has taken in the past. Instead, Khamenei chose to fire hundreds of projectiles at Israel’s second-largest city: one of the largest biggest ballistic missile attacks in history.

But Khamenei took this dramatic step for a reason—one that’s internal to Iran. The Islamic Revolutionary Guard Corps, Khamenei’s influential, ideological armed force, has been riven by divisions between its older, conservative commanders and its younger, radical ranks. The former generally favor exercising some restraint when it comes to Israel, whereas the latter want to go directly after the Islamic Republic’s nemesis. Typically, the older elite have held more influence with the supreme leader. But as more and more IRGC commanders and partners have been killed, the younger generations have gained the upper hand. They have done so by questioning the competence of their elders but also by suggesting that some IRGC elites are actually Israeli assets, including Esmail Ghaani, the IRGC commander who controls Iran’s Quds force—which, in turn, controls Iran’s network of proxy militias. After Israel killed Nasrallah, Khamenei’s calculus appears to have been shaped by this younger cohort. It is part of why Khamenei launched the October 1 attack.

The power of these young hard-liners is likely to grow in the years ahead. After successive intelligence failures, Khamenei can no longer rely on the old guard to run Iran. Even if he could, the IRGC’s radicals have time on their side. Khamenei is 85, and many of his top advisers are also elderly. The younger generations can wait for them to age out.

The Islamic Republic is therefore highly unlikely to grow more peaceful in the years ahead. The government will not moderate when its leadership changes. Instead, it will probably become more repressive, more violent, and more committed to destabilizing the world.

TO THE EXTREME

The IRGC is the backbone of the Islamic Republic. Established in 1979 to protect the clergy and consolidate Iran’s new theocratic regime, the Revolutionary Guards have gained power over seemingly every facet of the country’s economic, security, cultural, social, and political spheres. Once a relatively simple militia, the group now controls more than 50 percent of the Iranian economy and has its eye on gaining power over more. It has entrenched itself across Iran’s state bureaucracy and absorbed key ministries, including the interior and foreign ministries. It boasts 180,000 members stationed across Iran and the region.

The IRGC’s members span four generations. The first generation—its founders, who joined during the Iran-Iraq War (1980–88)—is primarily made up of Iranian revolutionaries who hailed from poor conservative and religious families. When Khamenei assumed power as supreme leader in 1989, most of this generation retired or was purged. (Many of its members were supporters of Ayatollah Hossein Ali Montazeri, who was the favorite to succeed Ruhollah Khomeini as Iran’s supreme leader, and were unhappy with Khamenei’s rise.) But those loyal to the new supreme leader stuck around, and he rewarded them with great economic influence over Iran—including by ignoring their corruption.

The second generation joined the IRGC in the decade after the Iran-Iraq War, when the Revolutionary Guards expanded into carrying out lucrative postwar reconstruction projects. Unlike those in the first generation, who joined for ideology and only later fell into wealth, members of this cohort signed up primarily in pursuit of riches. Many were comparatively uninterested in rigid Islamist principles. According to the memoirs of former Iranian President Hashemi Rafsanjani, a confidant of Khomeini, only around 15 percent of the second generation voted for the candidate Khamenei endorsed in the 1997 presidential elections.

This lack of loyalty set off alarm bells for the supreme leader. As a result, during the first decade of the 2000s, he began working to make the IRGC a more explicitly ideological group. Khamenei increased the time the IRGC spent on what the organization calls “ideological and political training,” or lectures, seminars, religious preaching, and religious ceremonies promoting Khamenei’s hard-line Shiite doctrines. The effort was a success. IRGC members who joined during the first decade of the 2000s—the Revolutionary Guards’ third generation—proved very faithful to the Islamic Republic’s principles and rule. They had few qualms, for example, about suppressing mass protests against the regime in 2009.

Khamenei, pleased by this loyalty, doubled down on making the IRGC ideologically pure. He dedicated additional time to political indoctrination, increasing such programming to 50 percent of all IRGC training. He reworked how new members were admitted. For most of its history, joining the IRGC was relatively easy for Iranians with a religious background. But starting in 2010, the organization replaced its open application process with one that was by invitation only, exclusively recruiting those who had been scouted and pre-approved. The most crucial criteria for receiving an invitation were religiosity and loyalty to the supreme leader.

The result is the IRGC’s fourth generation. It is even more radical than the third. Like their predecessors, these youngest members have been happy to suppress antiregime protests, openly gunning down demonstrators in 2019, 2022, and 2023. But they have also been disproportionately eager to deploy to Syria, where they have fought to prop up President Bashar al-Assad’s regime under the notion that they are defending a holy Shiite shrines. Finally, and with Khamenei’s encouragement, they have gone after less ideologically pure elements of the wider Islamic Republic, including Hassan Rouhani, a former Iranian president.

REAPING AND SOWING

In 2019, Khamenei issued a manifesto proclaiming that the IRGC should be the model for all state institutions. Iran’s bureaucracy, Khamenei argued, ought to be “young and hezbollahi” (ideologically hard line). He tasked his son and likely successor, Mojtaba, with following through on this command. Both men aimed to consolidate Khamenei’s personal control over Iran and ensure a smooth transition of power after his death.

Judged by the manifesto’s terms, Mojtaba’s reorganization was a success. Iran’s bureaucracy began hiring and promoting young IRGC radicals, leading to more hard-line foreign and domestic policies. But this transition came with drawbacks. Although the government’s new IRGC-trained officials had the right ideological résumés, they were not up to the task of actually running a government. As a result, their elevation worsened Iran’s structural crises, including its ailing economy and many environmental disasters. The political gap between the Iranian regime and the Iranian people widened.

For Khamenei, empowering younger radicals backfired in another way: it fostered divisions within the IRGC itself. Instructed by Khamenei to go after Iran’s unscrupulous and less Islamist leaders, the organization’s younger corps naturally began attacking some of its oligarchs, accusing them of being corrupted by financial interests and of being too timid in their dealings with the West. Some outwardly declared that IRGC leaders—including Ali Shamkhani, the former secretary of the Supreme National Security Council, and Mohammad Baqer Ghalibaf, Iran’s speaker of parliament—were engaging in graft.

This deepening of Iran’s crises prompted Khamenei to question his course of action. When Iranian President Ebrahim Raisi suddenly died in a May helicopter crash, Khamenei sought to use the resulting vacuum to slow the implementation of his manifesto. In the country’s snap presidential elections, the supreme leader endorsed Ghalibaf’s candidacy—part of an effort to hand the steering wheel over to the IRGC’s older and more experienced cohort.

But younger members, including those in the especially radical Basij militia, refused to fall in line behind the supreme leader’s selection. For these extreme ranks, Ghalibaf personified the very corruption they were determined to oust. Instead, they overwhelmingly supported the candidacy of Saeed Jalili, a politician with a cleaner record but hard-line ideological views. This support helped Jalili come in second in the election’s first round. Masoud Pezeshkian, a longtime parliamentarian from Iran’s elite reformist camp, came in first. Ghalibaf was knocked out.

Shocked by this loss of control, the IRGC’s older generation swung behind Pezeshkian in the runoffs, helping him win office. The new president has, in turn, tried to sideline young radicals from the upper echelons of the state’s bureaucracy. But the fight is hardly finished. The IRGC’s younger generation is more alienated than ever from its elders. And through Iran’s fight with Israel, they may have found a way to strike back.

EXPECT THE WORST

After Hamas’s October 7 attack on Israel, the country’s military began a series of strikes against the IRGC’s forces and those of its partners. Israel has targeted the IRGC officials and various Iranian-backed militias in Iraq and Syria. It has taken out Hezbollah’s senior leadership. It also struck an IRGC Quds Force command facility located in the annex of Iran’s consulate building in Damascus.

These attacks have infuriated almost all of the IRGC’s members, young and old alike. But the younger generations have also been outraged by Iran’s response. These radicals felt betrayed when Tehran refused to strike Israel directly after the latter’s initial set of attacks. Even after the IRGC sent hundreds of missiles and drones at Israel in April 2024, many younger officials were unhappy. Iran’s retaliation failed to deal real damage to its adversary, and IRGC radicals saw the response as largely symbolic.

Some younger members of the IRGC believe Iran has restrained itself out of fear. But others believe that something more nefarious is holding the country back. After the Hamas leader Ismail Haniyeh was killed in Tehran, and especially when Nasrallah was assassinated in Beirut, many radicals concluded that the IRGC’s oligarchy had been infiltrated by Israeli intelligence. According to this logic, some senior Revolutionary Guards officials are so invested in making money that they have been bought off by Israeli officials, offering them the coordinates of valuable targets and generally constraining Tehran’s response.

These allegations have put major pressure on Khamenei and the IRGC’s senior leadership to strike hard against Israel. It is, in part, why Iran launched such a massive attack this month. But the October 1 barrage, like the April one, will not silence the IRGC’s younger cohort. In fact, the group’s radicals are likely to be emboldened. Khamenei may find the young radicals frustrating, but he has probably concluded that their allegations are partially correct. It is hard to imagine that no IRGC officials are working with Israel since Haniyeh was killed by a remote-controlled bomb at an IRGC-run safe house. Khamenei will thus have little choice but to purge parts of his senior ranks and replace them with younger officials.

This inevitable move will exacerbate future crises, both within Iran and between the Islamic Republic and the wider world. Domestically, as the IRGC becomes more radical and aggressive, its crackdowns on dissidents will likely be harsher. Internationally, a more radical IRGC will lead Iran to expand its ballistic missile program, double down on supporting militias, and push for nuclear weapons. Tehran will become more determined to destroy Israel, remove U.S. forces from the region, and undermine the liberal international order.

Some analysts have expressed hope that, once Khamenei dies, Iran might correct course. But if anything, the supreme leader’s death will expedite this radicalization. Mojtaba has proved to be an even bigger supporter of the younger generations than his father was. Even if Khamenei’s son doesn’t succeed him, the supreme leader’s machinations have effectively ensured the mantle will pass to another younger, radical cleric.

Ultimately, the only thing that could prevent Iran from becoming more extreme is the unraveling of the regime itself. Such a collapse could be in the cards. The Islamic Republic is deeply, and increasingly, unpopular with its constituents, and most Iranians would almost certainly prefer a different, secular, and more peaceful government. But the regime has faced down decades of mass protests without being rocked. It has proved highly resilient to every challenge, despite its disastrous economic performance. For now, a more radical Iran is all but inevitable. No one should bet on anything less.