Iran’s presidential elections on 19 May will not only determine who and which political faction, moderate or conservative, will head the government during the next four years, but may also decide who succeeds Supreme Leader, Ayatollah Ali Khamenei.

The Guardian Council ^[1] announced on 20 April that six candidates, three from each faction, were ‘approved’ to contest the election. The council, of six clerics appointed by the Supreme Leader, and six jurists appointed by the Supreme Justice (himself a Supreme Leader appointee), reviews the eligibility of candidates for presidential, parliamentary and some other elected bodies.

The three moderate candidates are the president, Hassan Rouhani ^[2], Eshaq Jahangiri, Senior Vice President, and Mustafa Hashemitaba, a former Vice President. Of the conservative candidates, two are hard-line: Ebrahim Raisi ^[3], a senior cleric and a former Deputy Chief Justice and Attorney-General; and Mohammad Bagher Ghalibaf ^[4], mayor of Tehran and a former Commander of the Iranian Revolutionary Guards Air Force. The third, Mostafa Mirsalim, a former Minister of Culture, is a more traditional conservative.

Whether some candidates withdraw to avoid splitting their faction’s vote, remains to be seen. Candidates don’t know if they will be ‘approved’ by the Guardian Council so usually at least two members of the major groupings within each faction (technically, there are no political parties as such in Iran) will nominate in the event one, or more, are disqualified.

Amongst the conservatives, Jahangiri is a supporter of Rouhani but does not have his electoral appeal and he is likely to withdraw. Hashemitaba also has less electoral appeal than Rouhani, but, if he does contest, the split vote could affect the outcome.

Raisi and Ghalibaf are from the same hard-line conservative group. Ghalibaf has long standing presidential ambitions, having stood in 2005 and in 2013. If he withdraws, it’s unlikely the Guardian Council would approve his candidacy in future so he would be very reluctant to pull out. If Raisi stands firm and both contest the election, they’ll split the vote. Mirsalim has electoral appeal among moderate conservatives. Whether he would consider withdrawing to avoid further vote-splitting is not clear, but a three-way conservative split would significantly affect their chances.

This election will position future candidates to replace Ali Khamenei ^[5]. He has prostate cancer and could die or become seriously incapacitated within the term of the next president. Rouhani and Raisi are the front runners to replace him. Both are members of the Assembly of Experts which selects the Supreme Leader. If both contest the elections, victory would improve the winner’s prospects of becoming Supreme Leader.

It’s difficult to assess who will become president. Rouhani’s re-election is not a foregone conclusion ^[6], although all presidents since 1989 have won a second term. Rouhani’s campaign is focused on continuing his 2013 platform: economic development, a constructive role in seeking to resolve the multiple crises in the Middle East, improved relations with the West and social reform.

Progress on the first three has been mixed. The signing of the Joint Comprehensive Plan of Action (JCPOA) in 2015, and its implementation in 2016 was critical because it defused, at least in part, concerns about Iran’s intentions and ability to develop nuclear weapons. The lifting of many economic sanctions opened up opportunities for significant new foreign investment in Iran’s domestic economy, including the infrastructure sector, leading to the creation of desperately needed jobs. The close relationship between Iran’s foreign minister, Javad Zarif, and former US secretary of state, John Kerry, also helped Iran/US-West dialogue and understanding.

But continuing sanctions by many Western countries, especially the US, and uncertainty about the extent of US restrictions on international financial movements that would enable investment, have significantly slowed economic development. The Trump administration’s brake on the Iran-US dialogue has raised uncertainties about its future.

While the US Secretary of State, Rex Tillerson, announced on 18 April that Iran had complied with nuclear restrictions ^[7] despite strong allegations to the contrary, he added that US-Iran policy remained ‘under review’. He cited Iran continuing to be a sponsor of terrorism, especially by supporting anti-Israeli elements of Hamas and Hezbollah, and its support for Syria’s Assad government and backing of regional Shia militia, now engaged in proxy wars with Sunni militia, backed by Saudi Arabia and other Gulf states. Another factor is Iran’s alleged breach of UN restrictions on the development and test firing of nuclear-capable ballistic missiles and other military provocations in the Gulf area.

Potentially, the elections could deliver a hard-line conservative president, and down the track, a replacement hard-line Supreme Leader. Either, or both, would have significant implications, not only domestically in terms of the direction of economic and social change, but also for Iran’s international relations.

Rouhani’s re-election would allow him to continue his past policies, notwithstanding their deficiencies as perceived by the West. But delivery will be a challenge. If the US, backed by other regional states, raises its level of confrontation with Iran, it’ll be an outcome with no winners. Rouhani’s ability to shape domestic and international relations will be compromised, and could encourage the hard-liners to push for greater confrontation, regionally and internationally.