TEHRAN, Iran (AP) - Barack Obama's election and the chance of a leadership change in Iran offer the best hope in decades for direct talks between bitter enemies Iran and America.
But the differences run so deep - from Iran's nuclear program to Israel's future - that the prospect of a breakthrough or grand bargain is dim, at best.
Even those who support talks say they can foresee nothing broader than small steps to lessen tensions. Critics see certain failure.
"The Iranian regime will soon disabuse the next president of any utopian belief in the power of diplomacy," said Michael Rubin of the American Enterprise Institute in Washington.
Yet the possibility of rapprochement remains alluring to a world balanced precariously the past three years - and before that the last three decades - on the sharp edge of Iranian-American hostility.
U.S.-led efforts to curb Iran's nuclear program have largely failed, note many supporters of diplomatic outreach, leaving Tehran still busily taking the steps it would need to build a nuclear bomb, should it choose to someday. Outreach to pull and prod Iran toward cooperation is the best option now, they assert.
Even then, they advocate diplomacy only after Iran has chosen a new president this June, so as not to inadvertently boost the current hard-liner.
And they acknowledge, even then diplomacy could fail. Even so, "Let's call the Iranians' bluff," said Karim Sadjadpour, an Iran expert at the Carnegie Endowment for International Peace in Washington, and prove Iran is "the impediment in an improvement in the relationship, not the United States."
Obama himself has been cautious in recent months.
From the start, he has said he believes in "tough, direct diplomacy without preconditions," to pressure Iran to give up its nuclear program. The Bush administration long insisted that Iran first halt certain nuclear work, although it did engage in limited talks on Iraq.
Obama has since added that Iran's current hard-line President Mahmoud Ahmadinejad might not be the best person to talk to - a strong signal his administration will wait to see who wins Iran's presidency in June before acting.
When Ahmadinejad last week sent congratulations, Obama reacted coolly, saying only he would study the letter.
Iran, as is often the case, is also sending mixed signals.
Reformers are enthusiastic about Obama and have clearly been energized by his victory. One liberal Tehran newspaper this week trumpeted "Change in History."
But reformers have little power. Even if a candidate backed by reformers or moderates wins Iran's presidency in June, that new president would be hamstrung by Iran's supreme leader, Ayatollah Ali Khamenei. He sabotaged previous efforts in the late 1990s to improve U.S. and Iranian relations, during a period when a reformer was Iran's president and Bill Clinton was U.S. president.
Last week, Khamenei warned anew that Iran's hatred of the United States runs deep - a strong signal he considers anti-Americanism a pillar of the Islamic regime and won't give it up.
Khamenei believes "in his heart and in his mind that ... the Islamic Republic survives better when it has an adversarial relationship with the United States," said Sadjadpour, who recently studied decades of the reclusive leader's speeches and writings.
Iran's test-firing of a new generation of surface-to-surface missile that uses solid fuel, announced Wednesday, was another sign the country is likely to continue making moves that unnerve the West and Israel. In a speech coinciding with the missile launch, Ahmadinejad warned that Tehran would crush any country showing impudence toward Iran.
So are efforts at outreach pointless, since Khamenei ultimately makes the call?
No, insist supporters of diplomacy.
For one thing, Iran's people are much less hostile toward the United States. Many detest their country's current isolation, which hurts their pocketbooks, their pride and their children's future.
Hard-line clerics, even Khamenei, do have to pay some attention to public opinion, and even some hard-liners say Ahmadinejad has gone too far toward inflammatory rhetoric against Israel and the United States.
Ahmadinejad also is deeply unpopular because of Iran's failing economy. That could force Khamenei to give a new president some leeway to repair relations and ease the international isolation damaging the economy.
To take advantage of such a complex dynamic, Obama should focus first on small "confidence-building measures" such as cooperation on Afghanistan, where Washington and Tehran's interests have some overlap, supporters say. Obama's stated intention to draw down U.S. troops in Iraq also will remove a key tension.
Yet the central disputes remain unsolved: Iran's nuclear program and the regime's hostility toward Israel.
Even a more moderate Iranian president is unlikely to give ground on the nuclear program, with Khamenei holding the line and genuine public support for it in Iran. Iran insists the program is for peaceful purposes only.
Obama may think "he can convince Iran to give up its nuclear program, but this is a red line for Iran," said Saudi political analyst Khaled al-Dakhil.
Even on the nuclear issue, however, careful diplomacy on other issues could make some headway, said George Perkovich, a nonproliferation expert at the Carnegie Endowment.
Iran's intentions are key. What the world really cares about is preventing Iran from building nuclear weapons and threatening to use them.
Giving Iran a greater sense of security could make the country more likely to compromise, say Perkovich and others.
Toward that end, the U.S. might, for example, offer to broker a regional group including Iran and surrounding Arab countries to work on security issues, Perkovich said.
Such a move could increase Iran's feeling of security, since it now feels surrounded by hostile Arab neighbors and American troops, and believes America's ultimate aim is to overthrow its clerical regime. Retired Gen. John Abizaid, the former U.S. commander for the region, has been among those who say the West could live with a nuclear Iran as long as tensions eased.
Trust, however, is central to any such effort and trust remains in short supply.
Israel has the most to directly fear from Iran.
Facing looming elections of its own, its people are highly focused on Ahmadinejad's frequent calls for Israel's destruction and the long-range missiles Iran has developed to reach its territory.
Is hostility toward Israel another immutable pillar of Iran's regime, or is it something that could be talked out - and reassurances given - in delicate, perhaps secret negotiations?
Right now, no Israeli official believes so. Tzipi Livni, the more-moderate of the two candidates vying to lead Israel, has already warned Obama that "dialogue at this time is liable to broadcast weakness."