Iran’s missile program is a cause for international concern. Just last month, Iran launched a missile attack on Erbil, the capital of Iraq’s Kurdish region; in January 2020, Iran launched a similar, devastating strike on U.S. forces at Ayn Al Asad airbase in Iraq (in response to the U.S. killing of IRGC Quds force commander Qasem Soleimani earlier that month); and Iran was almost certainly behind the 2019 missile attack on Saudi Aramco facilities. Iran’s increasing willingness and ability to launch missiles at neighboring countries merits a coordinated, international response. Moreover, if Iran were to ever acquire a nuclear weapon, its unchecked missile program could allow it to hold entire cities at risk in the Middle East and potentially beyond. Yet opponents of the Iran nuclear deal go too far when they criticize the deal for not addressing Iran’s missile activities. If the United States is ever going to restrict Iran’s missile program through diplomacy, re-entering the 2015 Iran nuclear deal is the best – and likely only – way to make it happen.

Like any international agreement, the Joint Comprehensive Plan of Action (JCPOA), or Iran nuclear deal, was limited in scope. As the first agreement of its scale between the United States and Iran since the 1979 revolution, it could not solve every problem at once. The Obama administration was right to realize this during the negotiations. As former CIA Director John Brennan revealed in 2021, President Obama assessed early on that addressing Iran’s missile program in the JCPOA would be biting off more than the United States and its partners could chew. Iran sees its missile program as an important defensive capability given it is essentially surrounded by hostile powers. Indeed, if the missile issue were introduced in the nuclear negotiations, Iran would have countered by trying to expand the negotiations to include neighboring countries that have their own missile programs (posing potential threats to Iran) and that host U.S. missiles. Thus, rather than overburden an already complicated nuclear deal among seven countries and the European Union with even more parties and issues, the Obama administration wisely kept the deal targeted on the nuclear issue. Obama correctly assessed that it was best to cement the nuclear deal first and return to the topic of missiles in a follow-on agreement. At the time, with both sides aiming to build a record of compliance, this approach seemed highly credible.

In bringing Europe, China, and Russia to the table to limit Iran’s nuclear program, the United States scored a major diplomatic victory. The deal completely shut off Iran’s pathways to a nuclear weapon and fostered an environment to potentially discuss a follow-on agreement on Iranian missiles. But by abandoning the nuclear deal in May 2018 despite Iran’s continuing compliance with its strict nuclear restrictions and robust verification regime, the Trump administration threw all that away. 

When President Trump withdrew from the JCPOA – even though his own administration had repeatedly certified that Iran was adhering to the deal – he cited its lack of restraints on Iran’s missile activity as a key reason why. Yet just months after his withdrawal, Iran’s missile program grew even more audacious and menacing. By September 2019, Iran was launching missile attacks against Saudi Arabia that drastically reduced its ability to supply oil to the world market. By the ensuing winter, Iran was attacking U.S. forces in Iraq, and the United States and Iran grew extremely close to going to war.

If Trump’s policy was designed to limit Iran’s missile program, it obviously failed. Even worse, if it weren’t for the Trump administration’s reckless intransigence, the United States could have moved to build on the JCPOA and address Iran’s missile program five years ago. The fact that it squandered that opportunity rests squarely on Trump. 

Trump’s decision to withdraw from the JCPOA drew swift condemnation from former Vice President Biden, who campaigned during the 2020 presidential election cycle on re-entering the deal. Supporters hoped for a swift re-entry and a return to mutual compliance when Biden was elected. But despite a year of hard work at the negotiating table in Vienna, the United States still has not managed to re-enter the deal. 

The JCPOA’s critics are once again using Iran’s missile program as a reason to criticize U.S. reentry. But the Obama-era assessment that missiles are best left for a follow-on agreement still holds. Iran’s Supreme Leader, Ayatollah Khamenei, indicated before the nuclear deal was signed in 2015 that it would be an important test to see whether Iran could negotiate with the United States over “other matters.” Iran’s view today is that the United States has failed the test and is not a trustworthy negotiating partner. Thus, at a bare minimum, Iran will not be interested in discussing missiles until the United States returns to its commitments under the JCPOA and proves that it can follow through on agreements it makes. 

This prioritization of the nuclear issue is in the national interests of the United States, its allies, and its partners in the region. Ensuring Iran does not get a nuclear weapon was, is, and should be the top priority. Recently, two former top Israeli security officials wrote as much, arguing that both the Obama and the Biden administrations are right to focus on the nuclear issue first, as the more urgent threat, before addressing missiles. While it is true that prospects for a follow-on missile agreement are dimmer now than they might have been in 2015, there are causes for cautious optimism. Middle Eastern countries that initially opposed the deal may have been scared straight by Iran’s nuclear and missile progress since the Trump administration’s withdrawal – and may consequently have more of a self-interest in discussing regional constraints on missile advancement. In any event, failing to re-enter the nuclear deal will only make a follow-on agreement even harder to obtain. 

Moreover, a restored nuclear deal might on its own have salutary knock-on effects on Iran’s dangerous regional activities, including its growing propensity for missile strikes. After all, some of Iran’s most brazen actions occurred in the context of the near collapse of the deal, spurred on by the Trump administration’s “maximum pressure” campaign. Even if a restoration of the JCPOA has only a minimal positive effect on regional stability, a no-deal scenario is almost certain to drive relations further in a negative direction. In the event of no deal, relations between Iran and its neighbors are likely to be dominated by a perilous nuclear crisis, raising the risks of confrontation.

Furthermore, negotiations over a revived nuclear deal seem to be at a standstill largely because the United States and Iran disagree about other issues beyond the scope of the deal. As the State Department recently indicated, if Iran wants to discuss any issues it has with the United States beyond the scope of the nuclear deal, it will have to reciprocate by discussing U.S. concerns about Iran that exceed the deal. For decades, the United States and Iran have let their grievances fester. A renewed nuclear deal could reopen the door to addressing a broader range of concerns each side has with the other, including U.S. concerns about the Iranian missile program.

Thoughtful analyses exist on how to limit Iran’s missile capabilities. One approach would focus on preventing Iran from building long-range missiles capable of targeting Western Europe or the United States. An alternative approach might focus on curbing Iran’s most dangerous regional missile activities, such as transfers of missile materiel to unaccountable non-state groups. Of course, it is important to be realistic; Iran will demand a steep price for any restrictions, and even the most ambitious agreement is unlikely to roll back Iran’s current arsenal or restrict its ability to use missiles entirely. Consequently, the United States and its partners will still need to utilize a full range of other tools to keep Iran’s missile program in check. On the other hand, even a modest deal that commits Iran, and perhaps other regional countries, to minimal transparency measures such as pre-launch notifications for missile tests and space launches would go a long way toward preventing unwanted escalation and accidental war.

Before the United States can pick up where the Obama administration left off and pursue negotiations on Iran’s missile activities, it has to re-enter the nuclear deal. It has to prove that it is a serious negotiating partner, one that can keep its own commitments. In short, it has to restore its diplomatic credibility. This is not an easy task, but it is one the United States must pursue. 

The only thing worse than an unchecked Iranian missile program is an unchecked Iranian missile program along with an Iranian nuclear weapon. From Capitol Hill to Vienna, the United States should acknowledge that the best path to limiting Iran’s missile activity runs through the JCPOA.  

IMAGE: Deputy Secretary General of the European External Action Service (EEAS) Enrique Mora arrives at the Coburg Palace, venue of the Joint Comprehensive Plan of Action (JCPOA) meeting that aims at reviving the Iran nuclear deal, in Vienna on February 8, 2022. – After months of stalemate, progress has been made in recent weeks to revive the 2015 agreement that was supposed to prevent Iran from acquiring an atomic bomb, a goal it has always denied pursuing. (Photo by ALEX HALADA / AFP) (Photo by ALEX HALADA/AFP via Getty Images)