In the 30 years since Iran's Islamic Revolution, the world has grown used to Iranian leaders denouncing the United States.
"Those who say they want to create change -- this is the change: They should apologize to the Iranian nation and try to make up for their dark past and all the crimes that they have committed against the Iranian nation, and compensate for it," President Mahmud Ahmadinejad told a rally in Kermanshah, in western Iran, on January 29.
The firebrand Iranian president was speaking in response to U.S. signals that their two states should find ways to discuss the issues that have made them bitter enemies.
Just days earlier, freshly inaugurated U.S. President Barack Obama had expressed his willingness for talks in an interview with Persian Gulf-based Al-Arabiyah television, saying "it is important for us to be willing to talk to Iran, to express very clearly where our differences are, but also where there are potential avenues for progress."
Obama went on to pledge that the United States would, "over the next several months, be laying out our general framework and approach" to relations with Tehran.
"As I said during my inauguration speech," he added, "if countries like Iran are willing to unclench their fist, they will find an extended hand from us."
Why do the United States and Iran remain enemies three decades after breaking relations over the kidnapping of U.S. Embassy staff in the first year of the Islamic Revolution?Roots Of Anger
The Islamic republic accuses Washington -- which keeps Iran under unilateral sanctions -- of trying to topple it in pursuit of U.S. economic interests. It sees a precedent in the U.S.- and British-funded overthrow of Iran's Prime Minister Mohammad Mossadegh in 1953 after he nationalized his country's oil industry. That coup restored the Western-leaning shah to power until he himself was dethroned by the Islamic Revolution in 1979.
Washington, for its part, accuses Tehran of pursuing weapons of mass destruction and long-range missiles, sponsoring terrorist groups (notably Lebanon's Hizballah and Palestinian militants), and trying to sabotage the Mideast peace process.
In some people's eyes, those are reasons enough to keep any two sides apart. But there may be other factors, as well.
Geneive Abdo, a regional expert at the Washington-based think tank the Century Foundation, says that Tehran's confrontation with the West and its allies is one way the regime constantly renews its revolutionary legitimacy in the eyes of the Iranian public.
"It certainly allows the regime to perpetuate itself," Abdo says. "The Islamic Revolution has really survived based upon two basic pillars: One is its anti-Israel, anti-United States philosophy; and the other is its support for resistance groups, Hizballah and Hamas. And this is what makes it particularly problematic as the Obama administration tries to figure out how to approach Iran."
Abdo regards it as "unlikely Iran will retrench" on those two pillars, and calls that refusal "the challenge that every administration has faced since the [Islamic] Revolution."
Opportunities for any significant easing of bilateral tensions have been few and far between, but by most accounts include the period shortly after Mohammad Khatami's election as president in 1997. The rise of Khatami, who was perceived as a moderate, helped normalize relations with Europe. EU states boosted trade and sought a new policy of "constructive dialogue" with Iran.
But Khatami's early calls for a "dialogue of civilizations" that might include the United States were soon suppressed by Iran's supreme leader, Ayatollah Ali Khamenei. Khamenei, who holds ultimate political and religious power under Iran's constitution, branded reformists who were open to reconciliation as "either simpletons or traitors."Hard-Line Momentum
More recently, Iran's hard-liners have been in ascendancy, and the West increasingly united in a new showdown with Iran -- this time over its nuclear program.
Europe, with Washington and the UN Security Council, wants Iran to stop enriching uranium. All fear the work could lead to developing a nuclear weapon, though Tehran says it only wants to make fuel for nuclear reactors.
The standoff has lead to three rounds of UN sanctions targeting Iranian entities involved in the country's nuclear and missile programs.
At the same time, Washington has sought to convince banks worldwide to cut financial ties with Iran. That recently prompted a major European energy group, France's Total, to say it would likely not invest further in developing one of Iran's major natural-gas fields.
Any slowdown in Iran's ability to develop its oil and gas sectors could diminish its economy's ability to grow and absorb the hundreds of thousands of new people seeking jobs each year. The Iranian population has doubled over the past three decades, with more than 60 percent of the population now under the age of 30.
But Abdo says the country's leadership is determined to resist foreign pressure. Ironically, he adds, the Western-led push to make Iran step down in the nuclear crisis may actually strengthen the regime's hand.
"It's almost become a cliche, at least in Washington, that the [Iranian] public is for the nuclear program and that the regime is able to mobilize people around this issue; but it is true," Abdo says. "I think it is not nuclear power, per se, that Iranians favor. It is the bigger issue, which is [that] they want to be recognized as a legitimate country by the international community; they want to be recognized as a country that should be entitled to pursue its own deterrence, should be able to pursue its right to develop military nuclear power, as its neighbors have. They look at Israel, they look at Pakistan, they look at other nuclear powers, and they feel they are being isolated simply because they are Iranians."Regional Reach
Western powers have not just brandished sticks in the nuclear crisis, but also have offered carrots. The EU has promised Iran trade incentives and help with the rest of its nuclear-energy program if it gives up uranium enrichment.
But the right mix of carrots and sticks has yet to be found, and it remains to be seen how the newest element -- Obama's interest in talks -- might help.
As Iran faces new isolation on the world stage -- perhaps its greatest isolation since the Islamic Revolution's early years -- Tehran has been actively working to reassert its influence in its own region.
In Iraq, Iran is generally regarded as the major foreign power broker after the United States. Tehran's past and present support of Iraqi Shi'ite religious groups gives it powerful influence over the Iraqi security situation, as well as elements within its government. That is direct leverage that Iran can use in its ongoing confrontation with Washington.
Elsewhere, by providing funding and weapons to Hizballah in Lebanon and to Hamas in Gaza, Tehran has become a powerful player in the Middle East, in tandem with Syria. That gives Tehran leverage in its confrontation with Israel, which threatens to attack Iran's nuclear facilities.
Looking east, Tehran has also gained influence in Afghanistan, where it has restored economic and political ties with Kabul following the U.S.-aided toppling of the Taliban, whose own brand of Sunni extremism made the two bitter rivals.
In all these moves, the Islamic republic appears intent on assuring that, whatever happens on the global stage, Iran will not be isolated in its own neighborhood. That, in turn, suggests that Tehran believes it can still exact as heavy a price in a showdown with the West as the West can exact from it.
As Iran celebrates the 30th anniversary of its Islamic Revolution, RFE/RL looks at the legacy of the revolution and its effect on Iran and the world. More
Images Of Revolution
An audio slide show of Reza Deghati's iconic photos of the Iranian Revolution and the hostage crisis that followed. Play