ISTANBUL — The interviews were posted on the website of Iran's supreme leader this month, in Persian and English, quoting senior officials involved in nuclear negotiations over the years: a brief, tortured history of relations with the United States, timed to broadcast the worldview of Iran's establishment at a pivotal moment, as the Biden administration prepared to take office.

“There are certainly differences between the policies of Democrats and Republicans, as well as between the personality traits of Trump and Biden,” wrote Kamal Kharazi, a foreign policy adviser to the supreme leader, reflecting the guarded optimism among some in Iran at President Biden’s ascendance. “We should not rush. We need to see what the sum of American policy will be.”

But Mohammad Bagher Ghalibaf, Iran’s conservative speaker of parliament, represented another camp: skeptical of White House promises because of recent events and mindful of grievances that stretch back decades. “The enemy can’t be trusted,” he wrote.

Few countries have more at stake than Iran from the change in U.S. administrations. Over the last four years, the Trump administration upended the fragile bilateral relationship, threatening Iran with war, abandoning the nuclear deal Tehran struck with world powers and reimposing a near-total trade embargo. Last year, a U.S. drone strike in Iraq killed Iran’s most prominent military commander, nearly drawing the three nations into a regional conflict.

For many in Iran, a Biden presidency raised the possibility of, at worst, a gentler era, and perhaps even an agreement that would lead to the lifting of sanctions, helping to ease a crippling economic crisis as Iran reels from one of the worst coronavirus outbreaks in the world. But nothing was assured.

Given the high stakes, few governments have been as voluble as Iran on the subject of the U.S. transition. Every prominent Iranian official seems to have weighed in, sometimes repeatedly, including President Hassan Rouhani, who made his latest comments on the transition Wednesday.

“The ball is in Washington’s court,” he said. “If they return to their commitments, we will also fulfill our commitments.”

For normal citizens, the path forward was harder to predict, the future hard to see beyond the fog of daily privation. In recent years, as sanctions pummeled the economy, Iranians have watched their savings erode and the cost of everyday goods soar. The malaise, made worse by rampant corruption and government mismanagement, also paved the way for civil unrest. In 2019, after a government decision to raise fuel prices, Iran witnessed widespread protests and a fierce security crackdown that marked some of the worst violence in the country in years.

Now, nearly a year after Iran recorded its first case of the novel coronavirus, the country has suffered some 1.3 million reported infections and more than 57,000dead.

“I do not think Biden’s presidency is going to make any important change in our lives,” said Shabnam, 41, a teacher in Tehran who, like others, spoke on the condition that only her first name be used for security reasons. “To be honest with you, the degree and depth of hopelessness and despair in Iran is so high that I am not optimistic about any action by any Iranian or American politician,” she said.

The latest reasons for her disquiet were a recent decision by the supreme leader, Ayatollah Ali Khamenei, to ban the import of coronavirus vaccines made in the United States or Britain because he said they were “untrustworthy.” Then there was the sickly cloud of pollution that had descended on Tehran and other Iranian cities, some of the heaviest smog in recent memory.

“I have always been one of those who never wanted to emigrate, although I have had the resources and opportunities,” Shabnam said. The things that irked her — the pollution, the recklessness of leaders — were not new, but they felt like a final straw, and now she was trying to move to Canada, she said.

“I truly cannot imagine the lives of tens of millions who do not have an alternative, and their living conditions are getting worse day by day. I don’t think any American president could help with any of that,” she said.

Soudabeh, a 41-year-old architect in Tehran, was more optimistic. “The Iran-America relationship might improve, and tensions can decrease. Biden is more trustworthy when it comes to sticking to commitments, so military attack won’t remain an option anymore,” she said. “My guess is that a few sanctions are going to get lifted, and the price of dollars in Iran will drop a bit.”

In the past, though, once prices were hiked, increases were rarely rolled back, even after a crisis passed. “It has always been like this,” Soudabeh said. “In the past four years, the quality of life among Iranians almost at all levels of society has significantly worsened.

“With Biden, this might get easier,” she added.

A U.S. return to the nuclear deal “could be a beginning for the reconstruction of trust between Tehran and Washington,” said Hadi Khosroshahin, an Iranian foreign policy analyst and doctoral candidate at the University of Tehran.

It is hard to overstate how badly confidence has been eroded during the Trump years, he said. In Iran, the experience has revived memories of U.S. support for Iraq’s Saddam Hussein during the Iran-Iraq war and President George W. Bush’s classification of Iran as part of an “axis of evil,” Khosroshahin said.

The Trump era also sharpened domestic political rivalries in Iran between “pragmatists” — represented by Rouhani — and a more conservative camp suspicious of any engagement with the West. Biden’s best course of action will be to keep his distance from such internal disputes and avoid any appearance he wants to “change the arrangement of political powers in Iran,” Khosroshahin said.

He added: “If the U.S. wants to have Iran’s trust back, the new administration needs to be more generous” in its negotiations over any future deal. Otherwise, he said, discussions would remain frozen.

Mohammad Mohebi, a 39-year-old political activist, said any changes because of the U.S. transition would be “trivial” in Iran. “A few Iranians who travel between Iran and the U.S. might be able to travel more easily, but this is not a significant change,” he said.

“The problems are way more fundamental than a travel ban or some hundreds of barrels of oil,” he said, and they stretch back decades to the Iranian revolution. “Iranians have basically been deprived of a normal relationship with the whole world since 1979,” he said.