The ancient Greek historian, Herodotus, wrote that the Persians taught their sons “ to ride, to draw the bow and to speak the truth”.

Darius the Great, a contemporary of Herodotus, prayed to god to protect his country from “the lie” and warned two-and-a-half millennia ago that rulers would face rebellion if they lied to the people.

This is exactly what has happened in Iran after the authorities hid the truth for three days over the shooting down of a Ukrainian passenger jet, killing 176 people, including Iranian students heading to universities in Canada.

The undermining of an important Persian moral principle has caused outrage and thousands of protesters have taken to the streets to vent their anger.

“Death to liars” is among the chants calling for the removal of supreme leader Ayatollah Ali Khamenei.

The Islamic Republic has witnessed many protest movements over the years, most recently in mid-November over petrol price rises.

Security forces brutally killed hundreds of people and detained thousands more.

These movements have become more radical, more frequent and have spread across Iran.

The latest demonstrations, however, are different as they’re aimed directly at the regime as a whole and the supreme leader personally.

This time, those joining the struggle are the middle classes, students and women.

In response to internal and external pressures, the regime has adopted a bunker mentality, evolving into an authoritarian-theocratic centralised state presided over by an all-powerful supreme leader with no respect for constitutionalism.

Reformists are being eliminated from the power structure, with some prominent MPs disqualified from standing again in the upcoming parliamentary elections.

Even former president Mohammad Khatami, who still believes in the viability of the Islamic Republic, faces many restrictions.

There is no real freedom of expression or freedom of association, and many activists, environmentalists, human rights lawyers, and journalists are in prison.

In such desperate times, protests are becoming more violent. By suppressing demands for change and barring avenues to express peaceful dissent, the regime has unintentionally united large groups of society around the sole aim of ending Islamic rule.

Corruption, high unemployment and rampant inflation, a dysfunctional political system, international isolation, incompetence and economic mismanagement appear to be the main characteristics of the Islamic Republic.

The only department functioning efficiently, it seems, is the state repression machine.

To clamp down on dissent, investment has been ploughed into the Revolutionary Guard and the intelligence apparatus.

After four decades of turmoil, the Islamic Republic is running out of steam and the latest crisis has the potential to be a tipping point.

The recent defection of TV presenters, celebrities and sportsmen from Iran is seen as a barometer of changing public opinion.

The assassination of General Soleimani may have weakened the supreme leader’s resolve to fight back, and the seemingly easy way the US took out Soleimani has rattled senior commanders, who now fear the same fate.

It’s too early to say the regime is on the brink of collapse.

Despite mass discontent, the religious nature of the Islamic Republic and its anti-Israeli, anti-Western stance means the regime has kept much of its core base.

Among its supporters are those dependent on government handouts such as the families of martyrs and those working for the enormous religious and state bureaucracy.

Neither has there been any known defections from its diplomatic or ministerial ranks.

Other pressures continue to keep the regime afloat. Opposition is fragmented so the people can not unite the people under one platform.

An important element favouring the regime is the fear that the nation will disappear through “Syriasation”.

Iranians are fiercely nationalistic, and many wonder how to get rid of the regime without harming their country.

Indeed, President Trump’s recent threats to attack the country’s cultural heritage outraged many Iranians, including prominent monarchists, and many now feel trapped between two evils.

The Iranian regime can still save itself, possibly by releasing political prisoners, restoring press freedom and declaring national reconciliation.

But the leadership fear concessions may embolden the protesters. Past opportunities to reform the system have been squandered by the supreme leader.

Dictatorships, it seems, only realise the need for genuine change when it’s too late.

Many analysts believe that had the Shah of Iran introduced his reforms a few months earlier he may have saved his crown.

The regime may be able to suppress the protests for now. But pressures from the US are increasing and there are signs Germany and France may join the US and UK to create a new alliance to curb Iran’s nuclear and regional ambitions, causing even further isolation.

A combination of international sanctions and an internal backlash against the regime may eventually herald profound changes in Iran. 

Sadeq Saba is editor of Iran International and a former head of BBC Persian Television