February 11, the 31st anniversary of the Islamic Revolution, is shaping up to become a significant, and possibly defining, moment in the Iranian opposition's struggle against the regime - a struggle that has ebbed and flowed, but never been crushed, since last June's elections saw President Mahmoud Ahmadinejad reelected in a bitterly disputed vote.Opposition Web sites are encouraging supporters to come out onto the streets en masse to mark the anniversary by challenging the authorities, seeking to echo the events of 1979 by urging Iranians to "rise up" and asserting that "victory is near."For its part, the regime is warning that it will show less leniency in confronting street protests than it claims to have shown in the past."Given that these opponents are seeking to topple [the governing authorities], there will be no mercy," the state-run Islamic Republic News Agency quoted police chief Gen. Ismail Ahmadi Moghaddam as saying last week.During a recent visit to Teheran, and in subsequent telephone interviews, this reporter spoke to supporters and opponents of the regime, whose common refrain was that the an anti-regime activism is anything but over.In one telephone interview this week, an Iranian student activist said that the authorities were bribing and threatening students at the University of Teheran for information about the planned February 11 opposition activism, and that some activists have disappeared in recent days. "Students are being bribed to keep a look out for leads," said this activist. "Some are being threatened for information, and more people are disappearing. Some of us are being accused of being anti-Islam or going against our religion."Added another source in Teheran: "We have been threatened not to go out on Revolution Day, and we know the regime is making advanced preparations to silence us. Armored cars will be brought in [to the city] and more security forces." Traditionally on the anniversary, Iranians make a pilgrimage to the burial site in Teheran of Ayatollah Ruhollah Khomeini, who led the 1979 revolution to overthrow the Shah.The Internet postings urging more protests are themselves an act of defiance, since police chiefs have warned that they are monitoring the Web. Similarly, activists continue to defy the authorities by daubing opposition graffiti. Fresh graffiti on the walls of the streets of the holy city of Mashhad, this reporter was told, reads "From Ashura to Revolution Day, we will continue to fight."In street protests marking the Ashura festival last month, hundreds of people were arrested and at least eight people were reported killed in clashes with the security forces, including a nephew of "defeated" presidential candidate Mir Hossein Mousavi.Among those arrested was Mousavi adviser Alireza Beheshti, son of Ayatollah Seyyed Mohammad Hossein Beheshti, who was a close aide of Khomeini and the first judiciary chief after the 1979 revolution.There have been several reports that Beheshti suffered a heart attack while in detention, and some sources in Teheran claim that he has died, although there is no reliable confirmation of this."The regime always uses the excuse that their prisoner has mysteriously died of a heart attack, but we all know better," an opposition activist claimed. "Now they are killing the children of our martyrs, the children of those who gave their blood for this country. No one is safe."He went on: "The regime is showing us that there will be no mercy and no tolerance if we continue to protest. We can see this with the recent Ashura trials, condemning people to death and imprisonment. Our brothers and sisters are disappearing one by one."Other sources said that the authorities' ongoing efforts to suppress opposition now include the arrests of young children. A contact in Teheran described the recent arrest of an entire family of alleged opposition supporters, including their seven-year-old son. "Their relatives are desperate to find the boy," the contact said. At the same time, however, voices in support of the regime are also being raised."We are being tested, that's the best way for me to describe what is happening here," said an elderly shoemaker in Teheran, who then uttered a prayer in honor of Supreme Leader Ayatollah Ali Khamenei. "I pray for our Imam [Khamenei]. He is our rightful leader.""We are at war with the people who have lost faith, and who cannot accept the truth and leadership of the Imam," agreed Marjane, an 85-year-old Teheran woman. "Unfortunately, there are snakes and foreign powers at work to destroy our great nation. When we silence these destructive elements in society, our lives will be much better and the republic will be able to focus on those in need," said Marjane, who still works long hours as a housekeeper to support her bedridden husband."Imam Khomeini, may peace be upon him, was the 13th Imam and today Imam Khamenei has the responsibility placed on his shoulders," said a Teheran cab driver. "He has the responsibility to protect our nation and our faith from those who are trying to weaken us both inside and outside the Islamic Republic."My sister's son volunteers with the security forces," he added, "andhe said that those who dare disgrace our most holy and historicalremembrance will suffer and will not be spared. There are alreadypreparations to secure the city on that day. The people who come out[onto the streets to protest] on this day are enemies of our nation.""Religion needs to be protected, more so today," agreed an unemployedfather of three. "The Imam [Khamenei] is making difficult decisions.For instance, he ordered a mosque in Isfahan to be shut down because ofits ties to foreign powers. These are difficult times. We must not letAmerica and Israel get the upper hand. The Imam will seek revenge onthose who try to destroy us."