The Arab Spring; nuclear activity; mysterious killings at home and alleged assassination attempts abroad; house arrests; fears of impending air strikes; the storming of an embassy -- these are events that made 2011 the year of the threat in Iran.
And as made clear by Supreme Leader Ayatollah Ali Khamenei in November, Iran doesn't take such threats lying down. "We reply to threats with threats, he said. "Anyone who thinks of carrying out any act of aggression against the Islamic Republic of Iran should prepare themselves for strong slaps and steel fists from the powerful nation of Iran."
Some observers, such as Patrick Clawson, director of research at the Washington Institute for Near East Policy, would go so far as to say there is already a covert war under way between Iran and the West.
"There are already attacks, assassinations [of Iranian nuclear scientists], cyberwar, and I think the strong interest on the part of the West and Israel is to delay Iran's nuclear program as much as they can through sanctions, through sabotage, through encouraging defection of Iranian scientists and, when necessary through low-scale war like assassinations and cyberattacks," Clawson says. "No one's interested in a large-scale military confrontation. But let's be honest, there is a military confrontation going on."
No Spring In Tehran
The first ominous sign of a year fraught with tension came in January, when talks in Istanbul over Iran's controversial nuclear program stalled.
The so-called P5+1 -- permanent UN Security Council members Britain, China, France, Russia, and the United States, plus Germany -- walked away "disappointed" after the Iranian delegation set preconditions that included the United Nations dropping sanctions related to Tehran's nuclear activities. Iran blamed the West for the failure of the talks.
Then in February, the wave of protests that broke out across the Middle East and North Africa known as the "Arab Spring" hit close to home. That's when thousands of opposition protesters turned out for a banned rally in Tehran on February 14 to support the uprisings in Tunisia and Egypt.
"Mubarak! Ben Ali! Seyed Ali's turn," protesters chanted, implying Iran's leader would follow those of Egypt and Tunisia out the back door.
The regime's response was swift. Opposition leaders Mir Hossein Musavi and Mehdi Karrubi, the organizers of the protests, were placed under house arrest
to prevent them from rejoining the opposition rally. The next day, February 15, hard-line lawmakers called for their heads.
Little was heard of the two Green Movement leaders the rest of the year. And at points, the opposition movement, too, became silent
In June, protesters employed a different tactic to mark the second anniversary of the disputed 2009 reelection of President Mahmud Ahmadinejad. "We started walking on Vali Asr Street," one protester recalled. "As [expected], special forces were deployed on both sides of the street like a human wall. But people ignored them and continued walking on the sidewalks without chanting."
Saudi Plot, IAEA Report
Things heated up on the international scene in the fall, with the October announcement by the U.S. Justice Department that a plot to assassinate a Saudi diplomat
on American soil had been uncovered. Two people who, allegedly, were working under the direction of the Iranian government were charged.
Iran dismissed the allegation as "laughable," but a UN resolution condemning the action was supported by more than 100 countries.
President Barack Obama said no options were "off the table" in making Iran pay a price. "This is not just a dangerous escalation," he said, "this is part of a pattern of dangerous and reckless behavior by the Iranian government."
In November, it was back to the nuclear issue, when International Atomic Energy Agency (IAEA) Director Yukiya Amano announced the body's harshest assessment to date of Tehran's nuclear program
"The information indicates that Iran has carried out activities relevant to the development of a nuclear explosive device," Amano said. "It also indicates that, prior to the end of 2003, these activities took place under a structured program and that some activities may still be ongoing."
Iran, which maintains that all its nuclear activities are peaceful, called the report unbalanced and said it had been issued under pressure by the United States.
But Western countries ratcheted up pressure for yet more sanctions against Iran, including measures against its Central Bank and oil and gas sectors.
It all came amid what appeared to be increased covert operations aimed at slowing Iran's nuclear program and increasing speculation that an attack on Iranian nuclear facilities was being prepared.
Britain, which took the lead in introducing the new sanctions, immediately bore the brunt of Iranian anger when pro-government protesters stormed the British Embassy in Tehran on November 29.
Britain responded by evacuating its embassy personnel from Iran. And Britain's ambassador to Iran, Dominick Chilcott, has said he believes the attack on the embassy had the backing of the Iranian government.
By December, it was all drones. Within days after Iran claimed to have brought down a U.S. drone, Iranian television broadcast images of the bat-winged stealth aircraft
The undercarriage of the drone was shrouded with banners, one of which read: "The U.S. cannot do a damn thing," a direct quotation from the late Supreme Leader Ayatollah Ruhollah Khomeini.
Tehran called the drone overflight "tantamount to an act of hostility" and called on the United Nations for "clear and effective measures" against U.S. "aggression."
Fittingly, the year ended with a threat, made in the face of a threat.
In announcing on December 12 that Iran would soon hold a naval drill to practice the closure of the strategic Strait of Hormuz, through which about 40 percent of the world's oil traffic passes, parliament deputy Parviz Sorouri also gave warning.
"If the world wants to make the region insecure," Sorouri told the student news agency ISNA, "we will make the world insecure."
Based on reporting by RFE/RL correspondent Golnaz Esfandiari