While running for president of Iran in 2005, Mahmoud Ahmadinejad went out of his way to counter charges from opponents that his victory would bring to power "Islamic fascism" and the "Iranian Taliban."

The archconservative said Iran had bigger issues to deal with – economic, nuclear, and growing threats from the US and the West – than the status of women's head scarves, and the extent of personal freedoms that had grown under his predecessor, Mohammad Khatami.

But today Iran is in the grip of the most widespread crackdown since the 1979 Islamic revolution, with targets that range from women and student activists, to the media, to four Iranian-Americans accused of using US funds to undermine the regime. Analysts say the message of the repressive steps is clearly that hard-liners remain in charge, despite US efforts against the Islamic Republic and severe economic woes that led to the torching of 19 gas stations last month, when rationing was abruptly imposed.

"Their argument is that no matter what happens in Iran, no matter how many social disturbances exist, we are in control, and our position will not change," says Farideh Farhi, an Iran expert at the University of Hawaii in Honolulu.

This tougher "security outlook," as it is called in Iran, has been enabled by a top-down transformation of the ministries of intelligence, interior, and culture and Islamic guidance since Mr. Ahmadinejad and his hard-line allies took over, says Ms. Farhi. But it's also been facilitated by US actions, including $75 million for "pro-democracy" activities the regime sees as intended to foment a revolution.

"Ultimately, the policy that is pursued by the Bush administration is causing paranoia, and it is counterproductive [because] it benefits the hard-liners in Iran" by giving them a pretext to crack down, says Farhi.

This week, officials launched new investigations into two of the Iranian-Americans now held in Tehran's Evin prison: Haleh Esfandiari, a grandmother and Middle East expert with the Woodrow Wilson Center in Washington; and Kian Tajbakhsh, an urban planner who has worked with the Soros Foundation and the Iranian government.

'They're trying to instill fear'

But the US-Iran tug of war is just one factor in a growing number of hard-line moves that some argue have been aimed at preemptively quelling wider unrest, when the regime is under intense pressure both at home and abroad.

"They are trying to instill fear in the population, to let people know that while Iran may be getting a bit beaten up internationally, they are still very much in control domestically," says Karim Sadjadpour, an Iran analyst at the Carnegie Endowment in Washington. "And people should not think for one second that it is safe to agitate politically, to indulge themselves by engaging in criticism."

Iranian news organizations have been instructed not to report negative news regarding social unrest, gas rationing in the world's fourth-largest oil exporter, the nuclear program, or the impact of UN sanctions on Iran.

Last week, the head of the Ministry of Culture and Islamic Guidance warned darkly that he saw "signs of a creeping coup" in the Iranian media. On Wednesday, a ban was reinstated on a moderate Iranian news agency, just as, last week, a ban of seven years on Ham-Mihan newspaper was extended after a brief interlude of publishing.

In a one-month period this spring, security forces stopped or detained 150,000 people – women for insufficiently covered hair and tight-fitting clothes, and men for Western haircuts and attitudes. Most were released quickly, but many "hoodlums and thugs" were arrested, police said.

"This is a comprehensive security plan of the whole [Islamic] system, not just Mr. Ahmadinejad," says Saeed Laylaz, an economic and security analyst in Tehran. The crackdown is being pursued on three levels, says Mr. Laylaz: First, by "attacking ordinary people" to increase the police's street presence. Second, going after student activists – including eight who were arrested after chanting to Ahmadinejad "Death to the dictator" last winter – and intellectuals like the Iranian-Americans, and purging universities of liberal professors. And third, arresting a top insider on spying charges – former nuclear negotiator Hossein Mousavian – "as a warning notice to people who are thinking that they could do something against the system," says Laylaz.

Economic woes on the rise

Ahmadinejad was elected on the promise of bringing Iran's vast oil wealth to the "dinner table" of poor Iranians. But instead unemployment has risen, along with inflation, and Iran's small refining capacity – Iran imports 40 percent of its gasoline, at $4 billion each year – has forced an easing of long-standing subsidies at the pump. Now cars are limited to just less than a gallon a day, and motorists are fuming.

The violent reaction, when authorities gave only three hours notice that rationing would start at midnight, "could have been worse," but for the pre-emptive crackdown, says Mr. Sadjadpour.

"People sensed that the regime and the basiji [volunteer ideological forces] were really on a head-cracking spree the previous few weeks," says the analyst. "It made people think twice before going out onto the streets to vent their criticism."

Still, images of burning gas stations did little to calm nervous Iranians. "Unfortunately, Mr. Ahmadinejad did not [fulfill] his promises to poor people," says Laylaz. "This social unrest is an immediate and direct consequence of those policies.... And at the moment, the social structure of this country is absolutely fragile and sensitive about economic issues."

But those economic concerns have become tangled with myriad other social and strategic issues in Iran, which blend into a single "security" response from the regime. And the crackdown has had an impact, as Iranians – especially those with ties to Westerners – refuse invitations for cultural exchanges, conferences abroad, or lunch in Tehran where Western diplomats might be present.

Iranians with such ties who have been arrested and even imprisoned, report that their interrogators accused them of "serving the enemy" whether they knew it or not. A final report of BBC correspondent Frances Harrison last week, leaving after three years in Tehran, shows the scale of change.While numerous officials had attended the going-away lunch of her predecessor, not one – not even those from the Islamic Guidance ministry, who are often helpful on a personal level – came to her BBC farewell lunch."I did not take it personally," wrote Ms. Harrison. "The atmosphere is now one where Iranians are afraid to mix with foreigners for fear of being accused of spying."

Farhi says that what the regime wants to do is "break the kind of linkages that were created during the [former President Hashemi] Rafsanjani and Khatami period, because all these activities that people are being accused of were legitimate, and in fact promoted under previous administrations." [Editor's note: The original version misspelled Farhi's name here.]

That is the result of a new Machiavellian calculation, says Sadjadpour: "Whereas Khatami and the reformists said our best security is people's happiness, [this hard-line] worldview is that it is much better to be feared than to be loved.

"Their behavior is much more out of desperation than of strength," he adds. "It doesn't show that you are very confident about your place as a regime, when 67-year-old women are being suspected of undermining Iran's national security."