The shift is occurring against the backdrop of an economy so stressed that although Iran is the world’s second-largest oil exporter, it is on the verge of rationing gasoline. At the same time, the nuclear standoff with the West threatens to bring new sanctions.

The hardline administration of President Mahmoud Ahmadinejad, analysts say, faces rising pressure for failing to deliver on promises of greater prosperity from soaring oil revenue. It has been using American support for a change in government as well as a possible military attack as a pretext to hound his opposition and its sympathizers.

Some analysts describe it as a “cultural revolution,” an attempt to roll back the clock to the time of the 1979 revolution, when the newly formed Islamic Republic combined religious zeal and anti-imperialist rhetoric to try to assert itself as a regional leader.

Equally noteworthy is how little has been permitted to be discussed in the Iranian news media. Instead, attention has been strategically focused on Ahmadinejad’s political enemies, like the former president, Mohammad Khatami, and the controversy over whether he violated Islamic morals by deliberately shaking hands with an unfamiliar woman after he gave a speech in Rome.

Khatami, the lost hope of Iran’s reform movement, felt compelled to rebut the accusation because such a handshake is religiously suspect, but contended that the crowd seeking to congratulate him for his speech was so tumultuous that he could not distinguish between the hands of men and women. Naturally a video clip emerged, showing the cleric in his typical gregarious style bounding over to the first woman who addressed him on the orderly sidewalk, shaking her hand and chatting amicably.

The dispute over the handshake occurred during a particularly fierce round of the factional fighting that has hamstrung the country since the 1979 revolution. Far more harsh examples abound.

Young men wearing T-shirts deemed too tight or haircuts seen as too Western have been paraded bleeding through Tehran’s streets by uniformed police officers who force them to suck on plastic jerrycans, a toilet item Iranians use to wash their bottoms. In case anyone misses the point, it is the official news agency Fars distributing the pictures of what it calls “riffraff.” Far bloodier photographs are circulating on blogs and on the Internet.

The country’s police chief boasted that 150,000 people — a number far larger than usual — were detained in the annual spring sweep against any clothing considered not Islamic. More than 30 women’s rights advocates were arrested in one day in March, according to Human Rights Watch, five of whom have since been sentenced to prison terms of up to four years. They were charged with endangering national security for organizing an Internet campaign to collect more than a million signatures supporting the removal of all laws that discriminate against women.

Eight student leaders at Tehran’s Amir Kabir University, the site of one of the few public protests against Ahmadinejad, disappeared into Evin Prison starting in early May. Student newspapers had published articles suggesting that no humans were infallible, including the Prophet Muhammad and Iran’s supreme leader, Ayatollah Ali Khamenei.

The National Security Council sent a stern three-page warning to all the country’s newspaper editors detailing banned topics, including the rise in gasoline prices or other economic woes like possible new international sanctions, negotiations with the United States over the future of Iraq, civil society movements and the Iranian-American arrests.

The entire campaign is “a strong message by Ahmadinejad’s government, security and intelligence forces that they are in control of the domestic situation,” said Hadi Ghaemi, an Iran analyst for Human Rights Watch. “But it’s really a sign of weakness and insecurity.”

President Ahmadinejad and other senior officials have dismissed all the criticism as carping.