Iran has had a nuclear program since the country restarted it in the 1980s, has been under economic sanctions for it since the 1990s, faced the threat of war over it in the 2000s, and now has come through 20 grueling months of negotiations just to keep part of the program in place.
On its face, Iran's nuclear program makes very little strategic sense. Though Iran insists the program is only for peaceful purposes, it's far beyond what's necessary to generate nuclear power. And it's never made sense as an energy investment; other types of energy are more efficient for Iran, and its grid desperately needs upgrading.
"No sound strategic energy planning would prioritize nuclear energy in a country like Iran," Iran experts Ali Vaez and Karim Sadjadpour wrote in a Carnegie Endowment report.
This is why arms control experts believe that, as Monterey's Jeffrey Lewis put it, the program "could be used to make a bomb, and we think was originally intended to make a bomb." That said, there is an important distinction between developing nuclear weapons capability versus building an actual bomb (more on that later).
But it's not clear that even if Iran got a bomb, it'd be worth the price tag. By Vaez and Sadjadpour's estimate, Iran has lost $100 billion in foreign investment and oil sales alone because of the program.
All of this raises an important question, one that has not been asked much in this process: why? Why cling to a program that has invited so many problems, has not actually produced a warhead, and, even if it did, still probably wouldn't have been worth all of the costs?
The nuclear program's genesis
In 1974, the Shah of Iran said something shocking. "Sooner than is believed," Shah Mohammed Reza Pahlavi told Le Monde, Iran will "be in possession of a nuclear bomb."
The remarks caused a PR crisis. The shah later ordered Iran's embassy in France to deny he had ever said it. But the boast illustrates just how long Iran has been thinking about a bomb — and the nationalist thinking that's long underpinned it.
Iran's nuclear program has its origins in 1959, when the US set up the country's first nuclear reactor as part of an outreach meant to keep Iran in the anti-Soviet orbit. By the 1970s, Pahlavi had upgraded to a full-blown nuclear program.
Iran's leader wanted to establish Iran as the Middle East's leading and most advanced power, and saw nuclear development as a key symbol of Iran's ascension to regional dominance.
"A nuclear program became for [the Shah] a symbol of progress and power," Abbas Milani, a historian of Iran at Stanford, writes. That's where the US got off the train: Behind the scenes, the Carter and Ford administrations fought repeatedly with the shah about his nuclear ambitions.
Then, in 1979, Iran's Islamic Revolution deposed the shah. The new leadership shuttered the shah's pet nuclear project. Iranian leaders complained about being forced to buy "nuclear junk" from the West.
That changed with the Iran-Iraq war, which began in 1980 with Saddam Hussein's invasion of Iran. The war turned into a horrific stalemate, with many deaths on both sides. The US backed Saddam, and turned a blind eye when he repeatedly used chemical weapons against the Iranians — a shocking, gruesome tactic that remains fresh in Iranian memories to this day. Saddam had also done some work on a nuclear program.
Around 1984, as the war stretched on, Iran restarted its nuclear program, constructing nuclear facilities and purchasing enrichment technology from the Pakistani nuclear scientist A. Q. Khan, who had also sold to North Korea and Libya for their rogue nuclear programs.
In 1988, a US warship off of Iran's coast shot down Iran Air Flight 655, killing all 290 people on board. Though the shootdown had been a mistake, it was taken by Iran as a deliberate act meant as a threat of greater military action.
Iran's leadership, since taking power in the 1979 revolution, had seen itself as opposed to implacably hostile Western powers. Now it seemed to them that Iran was imperiled by an enemy on its border that was willing to use weapons of mass destruction and by a West so ruthless it would murder hundreds of civilians. The country was exhausted by eight years of war, and the threats seemed only to be growing.
It is not difficult to imagine how Iran's leaders might look at all this and conclude that they needed to take major steps to protect their country. We do not know for sure if Iranian leaders developed their nuclear program specifically for this reason, but it is important to understand the country's perilous security situation in the first decade after the 1979 revolution.
There are reports that in 1984, Iran's then-President Ali Khamenei privately told senior political and security officials that nuclear weapons would "serve Iran as a deterrent in the hands of God's soldiers" and secure "the very essence of the Islamic Revolution from the schemes of its enemies."
Khamenei has never publicly acknowledged these comments, and the reports of his supposed 1984 quote have not been independently verified. Years later, he issued a fatwa publicly denouncing nuclear weapons as un-Islamic. He became supreme leader in 1989 and has been the country's functional leader ever since.
Why Iran's program persisted: nationalism on top of security
Since 1984, Iran has remained deeply committed to its nuclear program. A 2007 US National Intelligence Estimate assessed "with high confidence" that "Iranian military entities were working under government direction to develop nuclear weapons" up until fall 2003.
So how is it possible that Iran could spend 20 years on a nuclear program, one widely thought to be geared toward nuclear weapons, and not come out with a single warhead? It's difficult to say for sure, because Iran does not acknowledge it has ever had a weapons program. Maybe it was not a high priority; maybe Iran wanted to take steps toward a bomb but not actually complete it. But one very likely factor is that, like a lot of countries that have thought about going nuclear, it may have simply had a hard time with the technology.
"The history in Iran [suggests it has] not had crack nuclear scientific operations ... in fact, they've been quite subpar," Jacques Hymans, an expert on nuclear proliferation at the University of Southern California, told me.
According to Hymans, the restarted program should, in theory, have been able to get a bomb or something close to it by the mid-'90s — in other words, 10 years into a program that's been around for 30.
During this slow development, the program began to take on ideological and political significance as well as the security logic that had likely prompted Tehran to start it. From the '80s onward, the United States loudly and publicly attempted to limit Iran's nuclear development, including imposing sanctions on corporations that worked with Iran on nuclear-related development in the 1990s.
This confrontation turned the nuclear program into a new kind of symbol of resistance. It represented revolutionary Iran's defiant willingness to stand up to hostile powers, as well as the Iranian technological prowess and power that it had symbolized under the shah. It was a symbol of both national pride and national independence.
The program "mutated into a symbol of Iranian defiance in the face of a supposedly hostile world," David Patrikarakos writes in his book Nuclear Iran: The Birth of an Atomic State.
That remains true today — and is a critical reason why the program persists well past the point that it stopped making much strategic sense.
Today's Iran: Does it want a bomb?
Things changed dramatically starting in 2002, when an Iranian terrorist group called the Mujahideen-e-Khalq revealed damning evidence to the world that Iran had been developing, in secret underground facilities, its nuclear program well beyond what anyone had known. The nature of the nuclear facilities and the technologies used in them made it very difficult to conclude that the program did not have a military purpose.
The next year, according to US National Intelligence Estimate, Iran appears to have stopped its nuclear weapons program: "We judge with high confidence that in fall 2003, Tehran halted its nuclear weapons program; we also assess with moderate-to-high confidence that Tehran at a minimum is keeping open the option to develop nuclear weapons."
Iran, though thought to be no longer driving toward a bomb after 2003, continued to expand its uranium enrichment and refused international demands that it shutter the facilities. The next year, United Nations nuclear agency inspectors found traces of weapons-grade uranium at a site in Iran.
The revelations, as well as Iran's defiance, led to an escalating series of sanctions from the United States, Europe, and the UN Security Council. The next 10 years were a process of brinksmanship and stalled negotiations as the world tried to convince Iran to abandon its nuclear program, which was now in formal violation of UN resolutions and the Nuclear Nonproliferation Treaty. Iran refused even as sanctions crushed its economy and it faced the threat of war.
No one really knows whether Iran's behavior during this time reflected a dead-set goal of securing a nuclear bomb, a desire to preserve the mere capability to build a bomb, or perhaps a more politically motivated aim of not caving to international pressure.
Within Iran's complex and often noisy political system, hard-liners were in power for most of this period; the presidency was held by a hard-liner, Mahmoud Ahmadinejad, from 2005 to 2013. For the hard-liners, a strong military is important to deter the Western powers they see as existential threats, but so too is it considered politically crucial to promote nationalism and to defy the international community at every turn. It is important to note that as of 2003, the US had toppled governments on both sides of Iran's border, having invaded both Iraq and Afghanistan.
Iran's behavior in this time "doesn't clearly indicate that they've made a decision to really go for it," Hymans says. The Iranians might instead have wanted to become something called a "nuclear threshold" state: a country that could produce a bomb very quickly if it decided it wanted to.
Whatever the motivation, Iran's investment in its nuclear program, despite all the costs, doesn't make a lot of sense in standard cost-benefit terms. It took Iran almost 30 years to get its nuclear program kind of close to a bomb, as it did in 2013, and the tolls to Iran's economic strength and political standing were severe.
Iran has not completely surrendered its program, but it has surrendered enough to satisfy the international community. Still, it is telling that Iran spent the past 20 months negotiating fiercely to keep this sliver of a program, which is far too small to be of real use for either nuclear power or nuclear weapons.
The reason is that the Iranian program has increasingly become a nationalist political project: Giving it up would be surrendering to the United States and Iran's enemies. Iran's leadership wants to prove that it can force the world to acknowledge its "right" to have a nuclear program — and the Iranian public expects them to be able to do it.
"The entire Iranian program is like a national airline. It's this incredibly expensive, preposterous thing that makes people feel better about their country," Monterey's Lewis said in April. "But there is just no reason that they need to do this."
This history makes the terms of the deal make much more sense
Once you understand how Iran's thinking about its nuclear program has changed over the past three decades — the way it shifted from being about security to being about politics — the nuclear deal starts to make a lot more sense.
In pure arms control terms, the United States came away with huge victories on every major issue. Nonproliferation experts almost unanimously think the deal severely limits Iran's program and makes it far harder to get a bomb, and that is not even to speak of the humiliating inspections and monitoring regime Iran has accepted. According to Aaron Stein, another nuclear expert, it "makes the possibility of Iran developing a nuclear weapon in the next 25 years extremely remote."
These kinds of concessions only really make sense if the primary purpose of Iran's nuclear program is no longer to build a bomb. If what it wanted instead was validation of its nuclear program from the world, then it got it.
Iran is allowed to maintain much of its major nuclear infrastructure; many of the crippling international sanctions are going to come off. Iran's leaders have defied the West's insistence that it abandon domestic enrichment entirely, and delivered hard, practical benefits to Iran's economy and its people.
Those benefits are pretty different from a nuclear warhead, in terms of the sort of value they bring to a country. But that just goes to show the degree to which this program is no longer about bombs. That could change if the hard-liners return to political prominence in Iran, but for now this deal makes strategic sense for the country.