Iran-Israel relations have worsened with time not only because of religion and differences in ideology, but also due to geopolitical reasons, says a Tehran-based expert. Although this is unlikely to change any time soon, a shift is still possible, he believes, but only if Israel abandons its persecution of the Palestinians.

It's difficult to underestimate the animosity between Iran and Israel these days. While the former threatens to "wipe the Jewish state off the map", the latter is doing everything it can to prevent that from happening, including allegedly sabotaging Tehran's nuclear programme, deemed a threat to regional security.

Israel believes that Iran is hiding the real purpose of its nuclear project and suspects the Islamic Republic of developing weapons of mass destruction to be used against the Jewish state.

Although Iran denies these allegations, saying their nuclear programme is intended for peaceful purposes only, Israel doesn't appear to buy these claims, allegedly working towards the disruption of the Islamic Republic's nuclear activity.

First, it was Stuxnet, a computer worm allegedly developed by Israel and the US that reportedly caused significant damage to Iran's nuclear programme. Then it was a number of assassinations of Iranian nuclear scientists. And more recently, it was a series of mysterious explosions and fires at key sites across the country that raised suspicions Tel Aviv was behind the attacks.

However, history remembers another type of relations between the two nations. Before the Islamic Revolution in 1979, Iran maintained stable ties with the Jewish state. Although the two never exchanged ambassadors, the countries did cooperate on a number of intelligence and military projects and Israel reportedly trained the Iranian Shah's secret service, the Savak.

Apart from military endeavours, the two nations also boasted an impressive trade turnover, with Iran even supplying oil to Israel, to the dissatisfaction of the Arab world. 

Back then, in Iran's largely secular society, Israel was not considered an enemy of the state and the "liberation of Jerusalem" wasn't at the top of the Iranian government's agenda, leading some Israeli experts to believe that the disputed city was not as important for Shiite Muslims as for other Muslims.

In his article for Mida, an Israeli news website that very often features pieces associated with the country's conservative circles, Dr Mordechai Keidar downplays the importance of Jerusalem to the Shiite Muslim world and suggests that the conflict between the two nations, which don't share a common border and have never had a face-to-face confrontation, is largely artificial.

"Shia has never agreed to believe the lie around the sanctity of Jerusalem sold to them by their Sunni peers", he writes. "For them, the third holiest place after Mecca and Medina is Najaf in Iraq, not Jerusalem", he added.

Religion and Ideology: Root of All Evil?

But not everyone agrees with Dr Keidar. Hamed Mousavi, a professor of political science from Tehran University, who specialises in the complex nature of Israel-Iran ties, says Jerusalem has always been important for Shiite Muslims, while the plight of the Palestinians and "Israel's occupation of their lands" was common discourse even in the days of the Shah, known for his support of the Jewish state.

"Even before the revolution, many people were dissatisfied with the policies set up by the Shah with regards to Israel, as they were unwilling to accept the treatment Palestinians had received", he explained.

For many, Jewish control of Islam's third holy city was unacceptable, and the seizure of Palestinian lands was considered illegal and immoral, feelings that only became stronger after the revolution which toppled the Shah.

Yet, the Palestinian cause and the religious factor surrounding it are not the only reasons for the discontent of Iranians with Israel. Mousavi explains this attitude by referring to the wide gaps observed between two conflicting ideologies.

"Israel with its imperialist ideology has been viewed as the main element of the American presence in the region. It was the embodiment of colonialism, whereas the new Iranian government supported the struggle of oppressed Muslims against western oppressors".

It was for this reason that shortly after the revolution Iran cut off ties with the Jewish state. Israelis, who were previously stationed in the country, had to escape to save their lives, and the keys to the Israeli mission in Tehran were given to then-Palestinian Liberation Organisation leader Yasser Arafat, who rushed to visit the country shortly after the ouster of the Shah.

Deepened Geopolitical Divide

Since then relations have only continued to get worse, and Mousavi pins the blame for the situation on regional geopolitics. 

"It all started with the [gradual] withdrawal of US troops from the region. [Once they, started to wrap up], regional powers started rising and that paved the way for Israel-Iran confrontation", said Mousavi, referring to the pullout of American forces from Iraq and the more recent decision to leave Syria and adding that he doubted the situation will ever go back to what it used to be before.

Presidential elections in Iran are set to take place in 2021, but just before they are not expected to change the current balance of power, a hope often expressed by Israeli experts.

And while the current system promises to stay intact, Mousavi says the only way for Tel Aviv to improve its relations with Tehran would be through "improving the conditions of the Palestinians", something that's unlikely to happen in the near future. 

"In recent years, their situation has only gotten worse. The two-state solution has been stalled and the recently introduced Trump peace plan didn't offer them any tangible political solutions. Without them, I am afraid, a change towards Israel is just out of question".