"The presence of people today on the streets all over Islamic Iran ... means that the enemy will never reach its evil objectives," Iranian President Hassan Rohani told vast crowds gathered Monday in Tehran to mark the date considered to be victory day in the country's 1979 Islamic Revolution.
Blasting what he described as a US "conspiracy," following President Donald Trump's decision to pull out of the 2015 Iran nuclear deal, the Iranian president vowed that his country would continue to pursue its missile programme to defend itself from external threats.
Renewed US sanctions have dealt a heavy blow to Tehran’s economy, with officials saying the move amounted to “economic warfare.”
In the streets of the capital, crowds burned US flags and chanted "Death to America," a chant that has been standard fare at anti-US rallies across Iran.
"The ‘Death to America’ chants have continued under [Barack] Obama right through to [Donald] Trump," comments Mitchell Belfer, president of the Euro-Gulf Information Centre in Rome. "It has not been a very good relationship."
"Of course, Trump does not help the situation with the reintroduction of sanctions, but then again the Iranians have been using the money that they gained from the sanctions relief to further fund quite nefarious groups in the Middle East," he told RFI.
Roots of Islamic Republic
Hatred for the "great Satan," the nickname for America coined by the founder of the Islamic Republic: Supreme Leader Ayatollah Ruhollah Khomeini, was a central tenet of the 1979 revolution.
It was after all America that installed Shah Mohammad Reza Pahlavi in power.
However, on 11 February, 1979, Iran’s army declared its neutrality, paving the way for the collapse of the US-backed monarch, the United States’ closest ally in the Middle East.
It was also the day that Khomeini declared Iran an Islamic Republic.
"It was the first regime in modern times where you have Shia ideology," explains Belfer. "Shia Muslims are [a] minority within Islam, but [the Islamic Republic] represents a new wave of religious extremism and it’s governed by their interpretations of Sharia law."
The Islamic Republic would also give birth to a new form of political Islam.
"The state ideology is about expanding its revolution," adds Belfer, comparing the aims of Ayatollah Khomeini to Lenin's views of the Soviet Union.
For Khomeini and today's Supreme Leader Ali Khamenei, a "revolution should not be in one country, it should be a worldwide revolution," he says.
This has spawned conflicts in various parts of the Middle East, including Yemen, Lebanon, Iraq, and Syria.
"There have been attempts in Saudi Arabia and Bahrein also to galvanise the Shia communities there," adds Belfer. "All along, the revolution that is being espoused by the ayatollahs is one of extending the revolution for the empowerment of a particular Shia form of Islam."
Rather than realising utopian dreams, the revolution failed to live up to its promises, reckons Armin Arefi, a Franco-Iranian journalist and author of the book A Spring in Tehran, the real life in the Islamic Republic.
"Forty years ago, Iranians went onto the streets because they wanted democracy," he says of this first "Spring" in the Muslim world.
"They wanted a government that would not be oppressive, they wanted their leader not to be a puppet of the Western world," he says.
Instead they got worse.
"Khomeini was not supposed to create an Islamic Republic where the veil for example would be mandatory," he told RFI.
Banned from Tehran in 2007, Arefi only recently returned to the country, to judge for himself the growing gap between the population and the regime.
"The population is very young, very modern, eager to have more contact with the Western world, whereas the regime still stands by its slogans against the US, against Israel," says the author.
This cultural clash comes to a head particularly in the debate on the Islamic veil.
"We see that the veil is not worn in a very Islamic way. You have hair coming out of the veil, it’s more loosely worn in the big cities of Iran. You have women for example who do not want to wear the veil even if they are forced to. They are taking pictures of themselves, selfies, and posting it on social networks."
There have been major protests during Khamenei's reign, but this popular anger has failed to take root.
"Lots of young Iranians are asking their parents why did you make a revolution to have worse?" says the Arefi. "But being against the regime doesn’t mean being able and eager to make a new revolution."
The past, he argues, is still very much present in young people's minds.
"Forty years ago, their parents made a revolution against the Shah, who was a dictator and they got worse."