Iran's President Raisi is dead. What does the leadership void mean for the country and the world?

• The sudden death of Iranian President Ebrahim Raisi in a helicopter crash comes at a difficult time for a country already facing deep economic decline, popular discontent and high geopolitical tensions.
• All eyes are now on what comes next for the Middle Eastern power, which is home to nearly 90 million people and whose government backs a number of regional proxy groups.
• Some analysts expect a fair degree of continuity, while also noting that this could present an opening for Iran's powerful Revolutionary Guard to gain even more control over the country's political direction.

The sudden death of Iranian President Ebrahim Raisi in a helicopter crash plunges Tehran into fresh uncertainty at a time when it already faces deep economic decline, popular discontent and war.

The helicopter carrying President Raisi suffered a hard landing on Sunday while returning from Azerbaijan in poor weather conditions, Iranian state media reported Monday. Iran's foreign minister, Hossein Amirabdollahian, also died in the accident.

All eyes are now on what comes next for the Middle Eastern power, which is home to nearly 90 million people and whose government backs a number of regional armed proxy groups including Gaza's Hamas, Lebanese Shia militia Hezbollah and Yemen's Houthis.

Some analysts expect a fair degree of continuity, while also noting that this could present an opening for Iran's powerful Revolutionary Guard to gain even more control over the country's political direction.

"This incident occurs against a backdrop of extremely high tensions in the region, which is already on edge due to the ongoing conflict in Gaza and recent military exchanges between Iran and Israel," Sina Toossi, a longtime Iran analyst and senior fellow at the Center for International Policy, wrote in a post on X.

"There is also growing rhetoric among Iranian officials about weaponizing the country's nuclear program," Toossi wrote. "Furthermore, the aging Supreme Leader Khamenei's succession is a significant factor in Iran's political landscape, compounded by a crisis of legitimacy facing the Islamic Republic. Raisi's death would contribute to an already volatile situation."

Elected in the summer of 2021 amid the lowest voter turnout ever for an Iranian national election, Raisi was a hard-line right-winger seen as a potential successor to the Islamic Republic's 85-year-old Supreme Leader Ayatollah Khamenei. The remaining contender for the position of Iran's most powerful leader is Mojtaba Khamenei, the supreme leader's son.

The 63-year-old Raisi was a harsh critic of the West, who cracked down heavily on the protest movement that swept the nation following the death of a young Kurdish Iranian woman, Mahsa Amini, while she was in the custody of Iran's morality police in September 2022.

Hundreds of people were killed during the crackdown, although this was not Raisi's first time overseeing death and executions; as a young prosecutor in Tehran in 1988, Raisi was part of a panel that directed the executions of hundreds of political prisoners, according to reporting by Amnesty International.

Asked to comment on his record in 2021, Raisi said, according to Reuters, "If a judge, a prosecutor, has defended the security of the people, he should be praised ... I am proud to have defended human rights in every position I have held so far."

His death now sets into motion a preestablished succession process that empowers current Vice President Mohammad Mokhber to assume the interim presidency and hold an election within the next 50 days.

Elections in Iran are considered unfree, as the powerful and ultra-conservative Guardian Council ultimately decides who is allowed on the ballot in the first place.

"What we've been seeing the last few years really is a power struggle between the IRGC on one side with other conservatives factions," Nader Itayim, Mideast Gulf Editor at Argus Media, told CNBC's "Capital Connection" on Monday.

Over the next 50 days of the interim presidency, the Revolutionary Guard's role in Iran's upper echelons of power is "going to remain intact and even potentially intensify," Itayim said. "That interim presidency ... [is] going to potentially pave the way for even more IRGC control over policies."

The relationship with Israel and the U.S.

Crucially, though, "Iran is not going to change course simply because of this," with regard to foreign and domestic policies, Itayim said.

"When it comes to the relationship with the U.S., and likely [with] Israel, nothing is really going to change there. There's wider issues at play between these countries and those are likely going to stay, those are deep-rooted issues."

Iran has refused to have formal diplomatic relations with the U.S. and rejected recognizing the state of Israel for decades, and remains under the weight of severe U.S. and Western sanctions. Attempts to make progress in talks to revive the Iranian nuclear deal repeatedly failed over the course of the Joe Biden presidency.

Amid Israel's war with Hamas in the Gaza Strip, Israel and Iran have traded missile and drone barrages, putting the region on edge and spiking fears of a wider war in the Middle East.

Raisi's death "comes at a difficult time for Iran," according to Sanam Vakil, director of the Middle East and North Africa program at Chatham House — but the world should still expect continuity, as the Iranian presidency is not where the state's power truly lies.

"The President is in theory second-in-command within the Iranian state, but he doesn't have the same sort of independence and ability to maneuver as president and many Western democracies do. He serves at the behest of Iran's supreme leader," Vakil said Monday.

"He also doesn't have independent foreign policymaking authority," she added. "So his death will really be more about filling his place finding someone to step up and step in to maintain cohesion within the system."

Iranian regime's 'rock-bottom credibility'

Public trust in Iran's government is at a dramatically low point.

Election turnout in the last few years has been among the lowest in the Islamic Republic's history, protests over issues from women's rights to corruption to water supplies routinely crop up around the country, and Iranians speaking to CNBC described local reactions to Raisi's death as "overjoyed."

"Raisi's departure offers the regime something of an opportunity, as his failures in office and general unpopularity had tarnished his reputation within the political system," Gregory Brew, an Iran and energy analyst at risk consultancy Eurasia Group, wrote in a note.

It "creates space for a new hardliner figure to take his place as president, offering the regime the opportunity to wipe the slate clean."

That isn't much comfort to many Iranians, who have seen their cost of living skyrocket and their access to the rest of the world shutter amid heavy sanctions, currency depreciation and government mismanagement of the economy.

"New elections are likely to demonstrate the broad dissatisfaction of the public as well as the regime's rock-bottom credibility," Brew wrote. "There is likely to be public resistance and possibly even some violence in response to another stage-managed election, though it is unlikely to present a serious challenge to security forces or the regime's hold on power."

Turnout at the polls would likely once again be low, and the new president "would assume office with very little legitimacy," he wrote. "Moreover, a new hardliner figure will face the same challenges as Raisi, including the current regional crisis, a sanctioned economy, and a looming succession crisis should Supreme Leader Khamenei die."