Weeks after Israeli warplanes pounded Iran’s capital last June, the country’s top generals stood in their socks at the entrance of a mosque in northern Tehran, mourning the men who had been killed in the strikes — leaders who they would now replace.
The strikes had caused the greatest single blow to Iran’s military in decades, wiping out the top leadership of the Islamic Revolutionary Guards Corps, the feared praetorian guard to the country’s supreme leader, Ayatollah Ali Khamenei.
Now, the question was how would this new generation of leaders, catapulted to the top, would guide the country through a singularly challenging period, including growing economic stress, the prospect of new international sanctions and regular threats of yet more military strikes from President Trump and Israel.
The answer came in recent weeks when those new leaders responded to nationwide protests with breathtaking brutality, opening fire on unarmed protesters and massacring thousands of people. At least one Iranian human rights group based in the United States said it had confirmed 5,002 deaths, including 207 members of the security forces, during the protests from Dec. 28 to mid-January. In their first official toll on Wednesday, the Iranian authorities said that 3,117 people had died.
On the surface, the bloody crackdown affirmed the unity of Iran’s ruling system — centered on the ayatollah and the Revolutionary Guards, estimated to number about 150,000 — and its willingness to take ruthless action to ensure its survival. But Iran experts said the bloody response was also a sign of the system’s growing weakness, exposing the limits of Ayatollah Khamenei’s 37-year rule as he wrestles with surging domestic unrest and intense foreign pressure at the same time.
On Thursday, Mr. Trump said that an American “armada” was heading toward Iran, but that he hoped he would not have to use it. He again warned the Iranian government against killing protesters or restarting its nuclear program.
That combination of factors put the ruling system under immense strain, said Afshon Ostovar, an Iran expert at the Naval Postgraduate School in California and the author of “Vanguard of the Imam,” a history of the Revolutionary Guards. “Right off the bat, they saw the protests as an existential threat,” he said. “They turned to live fire really quickly because their weakness was acute, and they knew it.”
With the ayatollah’s legitimacy under open challenge, the Revolutionary Guards are emerging as the core of the system. “You have this aging theocrat whose days are numbered,” Mr. Ostovar said. “And you have security forces that are taking an increasingly aggressive response to any threat to the regime.”
The upheaval has renewed comparisons between the Islamic Republic and the Soviet Union in the 1980s, before it collapsed.
Iran has seldom faced a greater array of challenges. Its network of regional proxies, including Hezbollah and Hamas, is in tatters. Its contentious nuclear program, estimated to cost tens of billions of dollars, failed to bring deterrence. Supplies of water and electricity are running low. Edicts forcing Iranian women to wear head scarves, a symbolic totem of the ayatollah’s conservative rule, are being openly flouted.
“The regime is ideologically bankrupt, economically at a dead end, and unable to rescue itself,” said Ali Vaez, the Iran project director for the International Crisis Group, a research body. “But it still has the will, and a fearsome capacity for repression.”
The ayatollah, who promised to strengthen the Islamic Republic after he came to power in 1989, has led the country into this predicament, critics say. His intransigence, rooted in resistance to the United States and Israel, but also in opposition to change at home, was once a pillar of his iron rule.
But that approach is seen by some as a mark of vulnerability, even by some of his own supporters, and analysts say his authority is at its lowest in decades.
The American and Israeli airstrikes in June initially provoked a nationalist surge inside Iran, as people across the political spectrum united against foreign aggression. “All these stupid attacks by the Zionists have brought Iranians together,” Abdulkarim Alizadeh, a retired commander with the Revolutionary Guards, said last summer as he left the mosque in northern Tehran.
Iran’s enemies had “miscalculated” if they hoped the attacks would provoke a popular uprising, Kamal Kharazi, a senior adviser to the supreme leader, told The New York Times in July. “On the contrary,” he said, “the war led to national unity.”
“We are prepared for all scenarios,” he added.
But defiance soon gave way to economic reality as the United Nations imposed new sanctions on Iran, causing the national currency to collapse. Protests on Dec. 28 in Tehran’s the main bazaars — whose merchants played a central role in the 1979 revolution — quickly spread across the country.
For years, the balance of power in Iran has been quietly shifting from Ayatollah Khamenei, 86, to the Revolutionary Guards. They are not only a security behemoth. They control a media empire, large parts of the economy, oil exports, seaports, an intelligence agency and an air force.
“They have everything that it takes to assume power,” Mr. Vaez said.
One scenario is that a figure favored by the Revolutionary Guards would seize power after the death of Ayatollah Khamenei, transforming Iran from a theocracy to a military-dominated country like Pakistan or Egypt.
Another scenario is that a faction of the Revolutionary Guards, fearful of American-backed regime change, could move against him first. “While a military coup was unthinkable a few years ago,” Mr. Ostovar said, “it’s becoming increasingly likely now because of all the pressures building on the regime.”
The picture is further complicated by the generational divide inside the Revolutionary Guards, he said.
While the older generation came of age during the war with Iraq in the 1980s, a time of deprivation and hardship, younger officers rose through the ranks at a time of Iranian expansion, as its influence spread through Syria, Iraq, Lebanon and Yemen.
Dismayed by the loss of that foreign network over the past few years, as well as by the severe damage to Iran’s nuclear program caused by the 12-day war in June, a more aggressive and assertive faction has emerged among younger members of the Revolutionary Guards, he said.
And while an older group of Revolutionary Guards has gotten rich — with children in elite private schools, homes in foreign countries and luxury cars — the younger generation has yet to taste much of that wealth, and wants to protect what it sees as its rightful reward.
“They know that if the regime goes, they will lose their meal ticket — and be first in line for retribution,” Mr. Ostovar said.
Where Iran goes from here is hard to know, but its future path has drawn comparisons with countries like North Korea, Turkey, Egypt and Russia. Still, predictions are fraught: In recent weeks, the internet has been restricted and a curtain of fear has fallen over the country, making information especially scarce.
Iran’s government has survived at least four earlier waves of protest, many of which also stirred speculation of regime change, while the ayatollah has defied rumors that he was dying of cancer or was in poor health.
But most analysts agree that, this time, the pressure on Ayatollah Khamenei and the Revolutionary Guards is likely to only increase.
“This is not a sustainable situation where you wait for an elderly leader to die to put things back in order,” said Mr. Vaez, drawing comparisons with the last years of Mao Zedong in China, or Leonid I. Brezhnev in the Soviet Union. In Iran, “the problem is the country doesn’t have the time to wait him out.”
