The Biden Administration faces a potential confrontation with a longtime rival that is better armed and more hard-line than at any time in its modern history.

By Robin Wright

December 27, 2021

Shortly after his Inauguration, Joe Biden appointed Rob Malley to be his special envoy for Iran. Malley, who is fifty-eight, grew up in France and was in the same high-school class in Paris as Secretary of State Antony Blinken. He graduated from Yale and Harvard Law School, won a Rhodes Scholarship, and clerked for Supreme Court Justice Byron White. Ruth Bader Ginsburg officiated at his wedding.

Malley has long experience with the Middle East. His father was a French journalist known for his support of anti-colonialist movements. Working on the National Security Council during the Clinton Administration, Malley participated in the Camp David peace talks. After they collapsed, in 2000, he broke with the conventional analysis that the summit had failed because of Yasir Arafat’s intransigence. Malley published detailed insider accounts about how the Israelis shared the blame, for making proposals difficult for Arafat to accept. Critics declared Malley rabidly anti-Israel. Former colleagues publicly called the attacks on Malley “unfair, inappropriate, and wrong.” After Clinton left office, Malley worked on Iran at the International Crisis Group, which tracks global conflicts. As part of his job, he met with Iranian officials and travelled to Tehran.

During the Obama Administration, he was on the team that produced the Iran nuclear deal, in 2015. The agreement, formally known as the Joint Comprehensive Plan of Action, was the most significant nonproliferation pact in more than a quarter century. Britain, China, France, Germany, and Russia were equal partners, but the United States had a virtual veto, and Iran knew it. During two years of tortuous talks, the Iranians often met the Americans in hotel hallways to thrash out issues. Malley, who deliberates with the intensity of a lawyer but is soft-spoken in person, was on a first-name basis with his Iranian counterparts. They exchanged family stories, cell-phone numbers, and e-mail addresses.

The agreement survived for only two years. Influenced by Prime Minister Benjamin Netanyahu of Israel and by Republican hawks, President Donald Trump abandoned the deal in 2018. He also imposed more than a thousand sanctions on Iran. They targeted the Supreme Leader, the Foreign Minister, judges, generals, scientists, banks, oil facilities, a shipping line, an airline, charities, and allies, such as the President of Venezuela, for doing business with Tehran. Trump also designated the Islamic Revolutionary Guard Corps, the country’s most powerful military branch, as a terrorist group—an action that the U.S. had never taken against another nation’s military, even the Nazi Wehrmacht.

During the Trump years, Malley was appointed president of the International Crisis Group. He kept in touch with some of his Iranian contacts. But when he became Biden’s envoy the Iranian diplomats he’d known for decades refused to meet with him. During talks in Vienna this past spring, the Americans stayed at the Hotel Imperial. The Iranians were eight blocks away, at the InterContinental. Enrique Mora, a Spanish diplomat for the European Union, carried proposals back and forth. Delegations from the other five nations consulted at a third hotel.

Malley compared proxy talks to a Woody Allen story, “The Gossage-Vardebedian Papers.” In it, two men play chess by mail. A letter goes “missing.” Moves are lost. Both players claim that they are winning. Infuriated, they stop playing before the game is finished. The Russian envoy, Mikhail Ulyanov, described the Vienna process as one of the strangest in modern diplomacy. “The aim isn’t to update an agreement or elaborate a new one,” he tweeted. “The goal is to restore a nearly ruined deal piece by piece. Was there a similar exercise in the history of international relations? I can not recollect anything like that. Can you?”

The bizarre diplomacy, Malley told me, took on unprecedented urgency in November. “We’ve seen Iran’s nuclear program expand, and we’ve seen Tehran become more belligerent, more bellicose in its regional activities,” he said. “They are miscalculating and playing with fire.”

The stakes extend well beyond Iran. The world’s nuclear order, already perilous, is now at risk of unravelling. Nuclear pacts hammered out in the last century are dated or fraying, as the U.S., Russia, and China modernize their arsenals. The Pentagon estimates that China could have at least a thousand bombs by 2030. The talks with Tehran are designed to prevent a tenth nation—the latest was North Korea, in 2006—from getting the bomb.

In the Middle East, Israel has had a nuclear weapon since the late nineteen-sixties. Saudi officials have also threatened to pursue the bomb if Iran obtains one. “The Iranian nuclear crisis can’t be viewed in a vacuum,” Kelsey Davenport, of the Arms Control Association, told me. “The broader nuclear order is in chaos.” The collapse of the talks with Iran—Biden’s first major diplomatic foray—would have consequences worldwide.

Both Washington and Tehran are violating the deal. A year after Trump abandoned the accord and launched his “maximum pressure” campaign, Tehran began breaching its obligations. It installed IR-6 centrifuges—which are much faster than the IR-1s allowed by the deal—and developed even more efficient models, including the IR-9. Centrifuges are tall tubes that enrich a gaseous form of uranium. They spin at supersonic speeds several thousand times faster than the force of gravity. Iran also increased enrichment from under four-per-cent purity—the limit in the agreement, and a level used for peaceful nuclear energy or medical research—to sixty per cent. “Only countries making bombs are reaching this level,” Rafael Grossi, the chief of the International Atomic Energy Agency, said in May. Weapons grade is ninety per cent, which, for Israeli officials, is a decisive juncture. “We don’t want to reach a point where we will have to ask ourselves how Iran was allowed to enrich to ninety per cent,” Zohar Palti, the former director of intelligence at Mossad, who is now at the Israeli Ministry of Defense, told me. The so-called “breakout” time for Iran to produce enough fuel for a bomb has plummeted, from more than a year to as little as three weeks. “It’s really short, and unacceptably short,” a senior Administration official said. “Every day they spin centrifuges, and, for every day they stockpile uranium, the breakout time continues to shrink.” Additional steps—including weaponizing the enriched uranium, marrying it to a warhead, and then integrating it with a delivery system, such as a missile—are required to field a bomb.

Israel has tried to slow Iran’s progress. In late 2020, Mohsen Fakhrizadeh, the father of Iran’s nuclear program, was assassinated as he drove with his wife and bodyguards to a weekend home. From more than a thousand miles away, the killer used artificial intelligence and a satellite connection to trigger a machine gun mounted on a parked pickup truck, spraying Fakhrizadeh with bullets. Tehran retaliated with a law that limited international inspections by blocking access to surveillance footage at nuclear sites. Experts fear that Iran may be considering a “sneak-out”—a covert path to a bomb. Tracking Iran’s facilities has become like “flying in a heavily clouded sky,” Grossi said.

The first six rounds of diplomacy this spring, Malley told me, made “real progress.” In June, he presented a nuclear package that included ending most of Trump’s sanctions. “The collective sense of everybody—obviously the Europeans, the Russians and Chinese, but also the Iranian delegation at the time—was that we could see the outlines of a deal,” he said. “If each side was prepared to make the necessary compromises, we could get there.”

The talks paused that month, after Iran’s Presidential election. Hassan Rouhani, the previous President and a reformist, had won in 2013 and 2017 on a platform of engaging with the United States. But Trump’s sanctions sabotaged the economic benefits promised by the nuclear accord, so in 2021 a majority of Iranians didn’t bother to vote. Ebrahim Raisi, a rigid ideologue and the head of the judiciary, was elected. The U.S. had already sanctioned Raisi, noting his role on a “death commission” that ordered the execution, in 1988, of some five thousand dissidents. At his Inauguration, in August, Raisi pledged, “All the parameters of national power will be strengthened.”

Malley had left his suits at the hotel in Vienna, expecting talks to resume before long. But five months passed, and Iran’s nuclear program advanced further. Malley eventually had his suits shipped home. By the time diplomacy resumed, in late November, Malley told me, Iran’s program had “blown through” the limits imposed by the J.C.P.O.A. “As they’re making these advances, they are gradually emptying the deal of the nonproliferation benefits for which we bargained,” he said. The Biden Administration has pushed back. “We’re not going to agree to a worse deal because Iran has built up its nuclear program,” Malley added. At some point soon, trying to revive the deal would “be tantamount to trying to revive a dead corpse.” The U.S. and its allies might then “have to address a runaway Iranian nuclear program.” Without a return to the deal, a senior State Department official said, it is “more than plausible, possible, and maybe even probable” that Iran will try to become a threshold nuclear state.

The wild card is Israel. In September, at the U.N. General Assembly, the new Israeli Prime Minister, Naftali Bennett, charged that Iran’s nuclear program had “hit a watershed moment, and so has our tolerance. Words do not stop centrifuges from spinning.” Israel is due to soon begin training for possible military strikes on Iran. During a visit to Washington in December, Defense Minister Benny Gantz urged the Biden Administration to hold joint military exercises with Israel. “The problem with Iran’s nuclear program is that, for the time being, there is no diplomatic mechanism to make them stop,” Palti told me. “There is no deterrent. Iran is no longer afraid. We need to give them the stop sign.” U.S. officials counter that Israeli operations have often provoked Tehran and set back diplomacy.

Iran can still reverse technological advances if a deal is reached. Its knowledge, however, is irreversible. “Iran’s nuclear program hit new milestones over the past year,” Kelsey Davenport said. “As it masters these new capabilities, it will change our understanding about how the country may pursue nuclear weapons down the road.” Even if the Biden Administration does broker a return to the accord, Republicans have vowed to scuttle it. In October, Senator Ted Cruz, of Texas, tweeted, “Unless any deal w/ Iran is ratified by the Senate as a treaty—which Biden knows will NOT happen—it is a 100% certainty that any future Republican president will tear it up. Again.”

As the nuclear talks foundered earlier this year, I flew to the Al Asad Airbase, in Iraq’s remote western desert, with Kenneth (Frank) McKenzie, Jr., a Marine general from Alabama, who heads U.S. military operations across the Middle East and South Asia. It was part of an extended tour of Iraq, Syria, Afghanistan, Qatar, and Lebanon. In the cavernous cabin of a C-17, he sat alone in a room-size container draped with an American flag. McKenzie’s military experience with Iran has been perilous and bloody. When he was a young officer, two hundred and forty-one marines were killed in the 1983 suicide bombing of U.S. peacekeepers in Beirut. It was the largest loss of marine lives in a single day since the battle of Iwo Jima, in the Second World War. The Reagan Administration blamed Iran and its then nascent proxies in Hezbollah. Almost four decades later, McKenzie told me that Tehran’s nuclear capabilities were far from the only danger it now poses.

Under Trump, hostilities between the United States and Iran escalated. They peaked in 2020, when Trump ordered the assassination of General Qassem Suleimani, the revered head of Iran’s Quds Force, the élite wing of the Revolutionary Guard. As Suleimani arrived in Baghdad to meet local allies, McKenzie called in an M-9 Reaper drone to fire four Hellfire missiles at the General’s convoy. Suleimani and nine others were shredded. His severed hand was identified by the large red-stone ring often photographed on his wedding finger.

Five days later, Iran fired eleven ballistic missiles—each carrying at least a thousand-pound warhead—at Al Asad Airbase. U.S. intelligence had tracked Iran’s deployment of the missiles, giving the Americans a few hours to evacuate their warplanes and half of their personnel. Lieutenant Colonel Staci Coleman, the commander of an air expeditionary squad, had to decide which of her crew of a hundred and sixty should leave and who was “emotionally equipped” to stay. “I was deciding who would live and who would die,” she later told military investigators. “I honestly thought anyone remaining behind would perish.” Many of the service members leaving Al Asad anxiously hugged the ones staying. No American military personnel had been killed by an enemy air strike since 1953, during the Korean War.

The first salvo struck around 1 a.m. Master Sergeant Janet Liliu recounted to investigators, “What happened in the bunkers, well, no words can describe the atmosphere. I wasn’t ready to die, but I tried to prepare myself with every announcement of an incoming missile.” The bombardment dragged on for hours; it was the largest ballistic-missile attack ever by any nation on American troops. No Americans died, but a hundred and ten suffered traumatic brain injuries. Trump dismissed the suffering at Al Asad. “I heard they had headaches,” he told reporters. Two years later, many of those at Al Asad are still experiencing profound memory, vision, and hearing losses. One died by suicide in October. Eighty have been awarded Purple Hearts.

The lesson of Al Asad, McKenzie told me, is that Iran’s missiles have become a more immediate threat than its nuclear program. For decades, Iran’s rockets and missiles were wildly inaccurate. At Al Asad, “they hit pretty much where they wanted to hit,” McKenzie said. Now they “can strike effectively across the breadth and depth of the Middle East. They could strike with accuracy, and they could strike with volume.”

Iran’s advances have impressed both allies and enemies. After the 1979 revolution, the young theocracy purged the Shah’s military and rebuilt it almost from scratch, despite waves of economic sanctions. Iran fought a ruinous eight-year war with Iraq in the nineteen-eighties that further depleted its armory. Its Air Force is still weak, its ships and tanks are mediocre, and its military is not capable of invading another country and holding territory.

Instead, the regime has concentrated on developing missiles with longer reach, precision accuracy, and greater destructive power. Iran is now one of the world’s top missile producers. Its arsenal is the largest and most diverse in the Middle East, the Defense Intelligence Agency reported. “Iran has proven that it is using its ballistic-missile program as a means to coerce or intimidate its neighbors,” Malley told me. Iran can fire more missiles than its adversaries—including the United States and Israel—can shoot down or destroy. Tehran has achieved what McKenzie calls “overmatch”—a level of capability in which a country has weaponry that makes it extremely difficult to check or defeat. “Iran’s strategic capacity is now enormous,” McKenzie said. “They’ve got overmatch in the theatre—the ability to overwhelm.”

Amir Ali Hajizadeh, a brigadier general and a former sniper who heads Iran’s Aerospace Force, is known for incendiary bravado. In 2019, he boasted, “Everybody should know that all American bases and their vessels in a distance of up to two thousand kilometres are within the range of our missiles. We have constantly prepared ourselves for a full-fledged war.” Hajizadeh succeeded General Hassan Moghaddam, who founded Iran’s missile and drone programs, and who died in 2011, with sixteen others, in a mysterious explosion. They had been working on a missile capable of hitting Israel.

Israelis call Hajizadeh the new Suleimani. McKenzie called him reckless. In 2019, Hajizadeh’s forces downed a U.S. reconnaissance drone over the Persian Gulf. He also orchestrated the missile strikes on Al Asad. Hours after that attack, his forces shot down a Ukrainian Boeing 737 passenger plane, with a hundred and seventy-six people on board, as it took off from Tehran’s international airport. Everyone perished. For three days, Iran refused to accept blame until, under pressure, Hajizadeh went on television to admit it.

Iran now has the largest known underground complexes in the Middle East housing nuclear and missile programs. Most of the tunnels are in the west, facing Israel, or on the southern coast, across from Saudi Arabia and other Gulf sheikhdoms. This fall, satellite imagery tracked new underground construction near Bakhtaran, the most extensive complex. The tunnels, carved out of rock, descend more than sixteen hundred feet underground. Some complexes reportedly stretch for miles. Iran calls them “missile cities.”

In 2020, the Revolutionary Guard marked the anniversary of the U.S. Embassy takeover by releasing a video of Hajizadeh inspecting a subterranean missile arsenal. As suspenseful music plays in the background, he and two other Revolutionary Guard commanders march through a tunnel lined with rows of missiles stacked on top of one another. A recording of General Suleimani echoes in the background: “You start this war, but we create the end of it.” An underground railroad ferries Emad missiles for rapid successive launches. Emads have a range of a thousand miles and can carry a conventional or a nuclear warhead.

Iran’s missile program “is much more advanced than Pakistan’s,” Uzi Rubin, the first head of Israel’s Missile Defense Organization, told me. Experts compare Iran with North Korea, which helped seed Tehran’s program in the nineteen-eighties. Some of Iran’s missiles are superior to Pyongyang’s, Jeffrey Lewis, of the Middlebury Institute of International Studies at Monterey, told me. Experts believe that North Korea may now be importing Iranian missile technology.

The Islamic Republic has thousands of ballistic missiles, according to U.S. intelligence assessments. They can reach as far as thirteen hundred miles in any direction—deep into India and China to the east; high into Russia to the north; to Greece and other parts of Europe to the west; and as far south as Ethiopia, in the Horn of Africa. About a hundred missiles could reach Israel.

Iran also has hundreds of cruise missiles that can be fired from land or ships, fly at low altitude, and attack from multiple directions. They are harder for radar or satellites to detect, because, unlike ballistic missiles, their motors do not burn brightly on ignition. Cruise missiles have altered the balance of power across the Persian Gulf. In 2019, Iran unleashed cruise missiles and drones on two oil installations in Saudi Arabia, temporarily cutting off half of the oil production in the world’s largest supplier.

The Biden Administration has hoped to use progress on the nuclear deal to eventually broaden diplomacy and include Iran’s neighbors in talks on reducing regional tensions. “Even if we can revive the J.C.P.O.A., those problems are going to continue to poison the region and risk destabilizing it,” Malley told me. “If they continue, the response will be robust.”

It may be too late. Tehran has shown no willingness to barter over its missiles as it has with its nuclear program. “Once you have spent the money to build the facilities and train people and deliver missiles to the military units that were built around these missiles, you have an enormous constituency that wants to keep them,” Jeffrey Lewis said. “I don’t think there’s any hope of limiting Iran’s missile program.” President Raisi told reporters after his election, “Regional issues or the missile issue are non-negotiable.”

From Al Asad, I flew with McKenzie to Syria in a convoy of Osprey helicopter gunships. Airmen were positioned at machine guns from an open ramp in the rear as we crossed the border. Our first stop was at Green Village, a former compound for oil-field workers on the Euphrates River. I was last there in 2019, for the final military campaign against the Islamic State. A small contingent of U.S. forces has been deployed in northeast Syria since late 2015 to aid and advise a Kurdish-led militia fighting isis. Officially, their mission is to contain isis remnants. Unofficially, they are also supposed to prevent Iran from gaining access to strategic border crossings from Iraq.

Abu Kamal, a once sleepy desert outpost, is sixty miles southeast of Green Village. isis jihadis seized it in 2014, and it became their main border-crossing point between Syria and Iraq. In 2017, three Iranian-backed Shiite militias and the Syrian Army captured it. Iran’s proxies have since absorbed—politically and militarily—much of the territory ruled by the Islamic State, including areas liberated by the Iraqi Army and the U.S.-backed Syrian Democratic Forces. “The best thing that ever happened to Iran was the U.S. coalition taking out isis,” a senior American military official told me.

Iran now uses Abu Kamal as a strategic hub for smuggling missiles and technology to its militia surrogates. The matériel includes kits used to upgrade rockets. By adding G.P.S. navigation, so-called “dumb” rockets, which are hard to control and rarely hit the target, can be converted into guided missiles that have a longer range and greater accuracy. The U.S. and the region “are worried by the degree to which Iran has been providing, sharing sophisticated weapons to its proxies,” Malley told me.

Under Suleimani, Iran expanded its “axis of resistance” with six core militias, including Hezbollah, in Lebanon; the Houthis, in Yemen; and Hamas and Islamic Jihad, in the Palestinian territories. In the nineteen-eighties and nineties, the resistance coalition carried out amateurish, albeit deadly, operations, such as suicide bombings and hostage seizures. Its forces today are coördinated and well armed, and project power region-wide. “Most countries look at what’s available and try to establish partnerships with what’s there. Iran created a network of regional proxies from scratch—its own alliance system,” Michael Eisenstadt, at the Washington Institute for Near East Policy, told me. “It’s the most cohesive alliance system in the region.”

The United States military is still vastly more powerful than anything built or imagined in Iran. Yet Iran has proved to be an increasingly shrewd rival. It has trained a generation of foreign engineers and scientists to assemble weaponry. It has dispatched stateless dhows loaded with missile parts for Houthi rebels, who have fired missiles at military and civilian targets in Saudi Arabia. It has provided the older “dumb” rocket technology to Hamas and Islamic Jihad. The majority of the “precision project” kits crossing at Abu Kamal go to Lebanon, where Hezbollah upgrades its short-range rockets and missiles to hit more accurately and to penetrate more deeply inside Israel. Hezbollah is now estimated to have at least fourteen thousand missiles and more than a hundred thousand rockets, most courtesy of Iran. “They have the ability to strike very precisely into Israel in a way they’ve not enjoyed in the past,” McKenzie told me.

The difference between Iran’s reach in 2016 and in 2021 is “simply remarkable,” a senior naval intelligence officer told me. Distributing missile technology is strategically cost-efficient. Missiles are a small fraction of the price of the defense systems needed to protect against them. Iran spends between two and three billion dollars a year to support the resistance coalition, according to the State Department. Yet its defense budget is also a fraction of what Saudi Arabia, an important U.S. ally, spends annually.

Iran now has enormous reach in several directions from afar. “If you can imagine a ring anywhere in Iraq that goes out, let’s say, seven hundred kilometres, draw your circle,” a senior intelligence official with Central Command explained. “Do the same thing in Yemen. Draw your circle. You quickly see the range and capability that Iran has provided. You can push it all the way to Syria, because, if they have it in Iraq, they probably have the ability also in Syria. What’s important,” he added, “is that the rings are now interlocking.”

Iran is gambling that it can harass the United States into eventually withdrawing from the entire Middle East, as it did from Afghanistan. Its actions across the region will have to be addressed in the not too distant future, Malley said. “If not, it will be a perpetual diversion from the U.S. shift to China,” and “a cauldron always being one step or misstep away from a much more dangerous conflagration.”

Seven American Presidents have failed to contain Iran’s political influence and military leverage. Distrust has only deepened since Iranian students seized the U.S. Embassy four decades ago and held fifty-two Americans for fourteen months. “Each side sees the other as so devious, malign, and mendacious,” John Limbert, a former hostage, told me. “Any proposal from the other—especially one presented as a concession—becomes another means to cheat and deceive.”

Rather than back down under Trump’s pressure, Tehran accelerated its nuclear and missile programs. Options, such as sanctions, are exhausted, the senior State Department official said. “That has clearly not produced the result that we all would have wanted.”

Besides diplomacy, President Biden has few preventive tools, and military action is not an attractive or effective long-term option. Five weeks after he took office, the U.S. tried to disrupt a nexus of Iranian proliferation. Two American F-15s dropped seven five-hundred-pound bombs on Abu Kamal. The air strike was in retaliation for a rocket attack, by an Iranian proxy, on a military base used by American forces in Iraq. The American bombs had little impact. “Without being able to crater the place, you’re not going to stop the flow,” the senior intelligence official with Central Command told me. “In fact, I think they were back up and running pretty quickly.” Israel has launched dozens of air strikes in or near Abu Kamal and hundreds more on Iranian targets in Syria. Weaponry still flows across the border.

Biden has also tried intimidation. In October, an American B-1B bomber flew from South Dakota to the periphery of Iran. Fighter jets from Egypt, Israel, Saudi Arabia, and Bahrain escorted it across the Middle East. Since November, 2020, the United States has dispatched seven missions of B-52 bombers—nicknamed buffs, or “big ugly fat fuckers,” for their size and shape—around Iran. Even senior officials wonder about the efficacy of such tactics. The naval intelligence officer said, “I think to disrupt is easy, but sustained pressure to change behavior? That requires a decision to develop some capability on the ground in areas that, I think we’ve said, we’re just not that interested in, from a national-priority perspective.” U.S. officials concede that the flights do more to reassure allies in the region than to scare Iran.

Tehran seems undaunted. In October, it launched a drone attack on Al-Tanf, a military outpost in Syria where two hundred Americans have been based. Al-Tanf’s wider strategic value is its position on the vital highway between Baghdad and Damascus—and the route to Lebanon and the Mediterranean. Unofficially, the U.S. goal is again to hinder the transfer of Iranian weapons and influence. A Hezbollah news site described the Iranian attack on Al-Tanf as “a new phase in the confrontation” to force America out of the Middle East.

Iran’s surrogates in Iraq have taken on bigger targets, too. On November 7th, three quadcopter drones attacked the home of the Iraqi Prime Minister, Mustafa al-Kadhimi. Several guards were injured. The strike followed a parliamentary election in October, when Iranian-backed parties lost dozens of seats and claimed voter fraud. In a television interview, McKenzie accused Iran’s allies of “criminal” acts against a head of state. “What we have seen are groups linked to Iran that see that they cannot legally cling to power, and now they are resorting to violence to achieve their goals,” he said. The attack was initially tied to two Shiite militias—Kata’ib Hezbollah and Asa’ib Ahl al Haq. Both have engaged in weapons transfers at Abu Kamal.

In September, I met twice with the new Iranian Foreign Minister, Hossein Amir-Abdollahian, when he attended the U.N. General Assembly in New York. For years, he was considered Suleimani’s man in the Foreign Ministry. He noted that the United States had walked away from the nuclear agreement and imposed massive sanctions. “If the wall of mistrust can be reduced, then there may be some commonalities, but it’s such a high wall,” he said. “When we’re forbidden to access our own money for life-saving vaccines, can there be even a trace of trust between the two countries?” To prove American good will, Amir-Abdollahian said, Biden must first lift sanctions and help free billions of dollars of Iranian assets frozen in other countries, such as South Korea. “If we reach an agreement, it can be used to make further progress,” he said. “If it fails, we have already said that we do not tie the future of the country to the J.C.P.O.A.”

Malley proposed that the two countries agree to return simultaneously to the accord, and then decide on a sequence of steps. The Administration does not want to reward Iran without proof that it is reversing its nuclear advances, reverting to older centrifuges, reducing its uranium stockpile, and allowing full inspections. Working with five world powers, the U.S. may somehow manage to restore the nuclear deal. Iran does face unprecedented challenges at home and from the outside world. The original revolutionaries are dying out, and their grandchildren are more into social media than ideology. In 2021, sporadic protests erupted as more than three hundred cities dealt with shortages of water and electricity; demonstrators also took to the streets to complain about low or unpaid wages. But if diplomacy stalls and Iran continues to accelerate its nuclear program, the senior Administration official warned, the U.S. could face a nuclear crisis in the first quarter of 2022.

McKenzie has analyzed how a conflict with Iran might play out. “If they attack out of the blue, it would be a bloody war,” he told me. “We would be hurt very badly. We would win in the long run. But it would take a year.” Or potentially more, as the United States has learned in Afghanistan and Iraq. And a full-scale military campaign by Israel or the U.S. would almost certainly trigger a regional war on multiple fronts. Iran is better armed and its military and political powerbrokers more hard-line than at any time in its modern history. The nuclear deal could be just the beginning—and the easier part of the Iran challenge for an eighth American President. ♦Published in the print edition of the January 3 & 10, 2022, issue, with the headline “Overmatch.”

Robin Wright, a contributing writer and columnist, has written for The New Yorker since 1988.