America Needs a New Nuclear Nonproliferation Toolkit

President Trump’s special envoy for the Middle East has been busy. In between his efforts to bring an end to the Russia-Ukraine war and maintain the fragile ceasefire between Israel and Hamas, Steve Witkoff has also been working to broker a deal with Iran on its nuclear program. But while Witkoff has been actively engaging counterparts from Moscow to Jerusalem, little progress appears to have been made with Tehran. 

To be fair, even if Iran’s nuclear file had Witkoff’s full attention, a number of challenges likely would have stymied his efforts to secure and implement a deal. Among the most fundamental of these is a diplomatic playbook that is insufficient to address the challenges of the current geopolitical environment. For decades, the United States has relied on a robust diplomatic toolkit underpinned by its predictability and a powerful network of allies and partners to prevent nuclear proliferation. But Trump and his administration, including Witkoff, have abandoned traditional methods in favor of personalist diplomacy. While this can be helpful in some contexts, it also has its shortcomings.

That said, the likelihood—and wisdom—of returning to traditional methods of diplomacy in the context of nuclear nonproliferation is questionable. Today’s world and domestic politics in the United States are no longer conducive to prolonged pressure on adversaries and credible assurances to allies, not least of all because allies are now concerned about threats from the U.S. And the cadre of civil servants that had brought continuity across administrations has now been lost to massive workforce cuts. A changing international landscape with new threats of nuclear proliferation—coinciding with seismic shifts in how Americans and their leaders view themselves and the world—requires a reassessment of the nonproliferation toolkit’s efficacy if the U.S. wishes to respond successfully to future proliferation challenges. The case of Iran encapsulates this challenge—and provides an opportunity.

Iran’s Nuclear Program

In the late 2000s, the United States helped build a coalition that would be unlikely today to prevent Iran from developing a nuclear weapon. This coalition—led by the U.S. and composed of China, Russia, France, Germany, the United Kingdom, and the European Union—isolated the Islamic Republic and created a robust international sanctions regime that forced Iran to the negotiating table in 2012, conceding to restrictions on its nuclear program. 

By 2015, the parties reached an agreement known as the Joint Comprehensive Plan of Action (JCPOA) that would be implemented briefly before Trump withdrew from it in 2018. (That Tehran’s nuclear program has remained as relatively boxed in as it has—having gradually moved toward removing the constraints from the deal—is itself thanks to the agreement’s restrictions.) By the time President Biden took office in 2021, Trump had rebuilt and expanded the United States’ sanctions architecture targeting not just Iran’s nuclear program but a host of Iranian malign activities. These additional sanctions chiefly sought to stymie the regime’s support for terrorism—a policy the administration dubbed its maximum pressure campaign. As Trump described it, he wished to pressure Iran’s leaders to cut a deal that would replace the one struck under President Obama. Instead, Trump left office amid heightened tensions with the Islamic Republic, which culminated in tit-for-tat escalation throughout the final months of Trump’s first term. 

Upon entering office, Biden sought to return the United States to the deal that some of his team had helped forge under Obama. He also ambitiously aimed to address criticism of its original agreement, including its sunset provisions and scope (or the fact that it didn’t restrict certain problematic Iranian activities). A return to the JCPOA, the Biden administration hoped, would provide the foundations for a “longer and stronger” agreement encompassing other aspects of Iran’s behavior, including its missile program. After months of marathon negotiations, the Biden team (on which I served) was unsuccessful in its efforts to revive the deal, much less build on it. And having mistakenly based its policy toward Iran on the JCPOA, the administration failed to address the many other areas of concern with the regime’s behavior. As Biden ceded the White House to Trump to serve a second term, Iran’s nuclear program continued with very few constraints. 

Within months of Trump’s return to power, his administration proposed to negotiate a new deal with Iran. At the same time, Trump lent a helping hand to Israel, engaging in military strikes against components of Iran’s nuclear program. And a few months later, the United Nations snapped back UN sanctions on Iran. 

Though the level of damage inflicted to Iran’s nuclear capabilities remains a matter of speculation in the public domain, it is clear that Tehran can reconstitute its nuclear program and may even resume efforts to weaponize. Iranian leaders’ decision to take such action will be determined by how willing they are to simply leave the nonproliferation treaty outright or continue to take steps to build up their capabilities while remaining a party to it.

Regardless, it is safe to assume that Iran’s nuclear program will remain a nonproliferation challenge for the foreseeable future. And this, against the backdrop of a receding America, and the return of a geopolitical climate in which nations see it as prudent to develop their own capabilities and stand on their own two feet rather than rely on international agreements. Today, decades of work performed by policymakers and lawmakers from both parties to ensure continuity have been abandoned, and with it, so have the pillars of predictability upon which international affairs in general and nonproliferation policy in particular stood. 

The End of Predictability

After 2016, Iran and other adversaries recognized that they could wait out any administration, and conversely, no U.S. president could ensure continuity beyond their administration. The nuclear deal secured by Obama arguably could’ve meaningfully changed the trajectory of Iran’s nuclear program had Trump not abruptly left it just two short years after its implementation started, and Trump’s maximum pressure campaign may have yielded some results had it lasted. To be sure, the Biden administration maintained much of the maximum pressure structure, but its officials often and intensely signaled that it wanted a deal, and its enthusiasm was likely interpreted as a willingness to sacrifice holding Iran accountable. But while Americans and U.S. allies could for decades take for granted that U.S. administrations—both Republican and Democratic—would maintain a lot of predictability in their foreign policy, this is no longer the case today. Friends and foes alike now expect the U.S. to do an about face every four to eight years. 

Not only do these shifts make it difficult for the United States to send coherent signals to its allies and adversaries, but the uncertainty also handicaps the U.S.’s ability to build meaningful diplomatic channels and coalitions, fruitful sanctions architectures, and a credible military deterrent. When one administration prioritizes allies and partners as a cornerstone of its national security strategy and the other threatens to leave NATO, the whiplash makes allies contemplate their own nuclear option rather than depending on an increasingly unreliable ally and security guarantor. 

Adding to these challenges are the exodus of thousands of career public servants, including many who had dedicated their lives to advancing the United States’ nonproliferation efforts across the interagency community, a public increasingly skeptical of traditional U.S. foreign policy, a more isolationist Washington, looming or actual lapses in appropriations, and a string of continuing resolutions in Congress that make long-term planning more challenging. Trump’s moves in trade and monetary policy also risk undermining the U.S. dollar in ways that will have long-term consequences for the U.S.’s economic power and the Treasury Department’s ability to levy it against nuclear proliferators and malign actors. Finally, the toolkit’s overuse or misuse vis-a-vis its allies and partners (as was the case after Trump withdrew from the JCPOA back in 2018) jeopardizes its utility and sharpness. 

Many of these trends are likely here to stay. So, to have a sound nonproliferation approach in this environment, the United States must rethink its existing framework.

The Need for a New Toolkit

First, the United States can no longer expect to build coalitions that involve Russia and China. Even traditional allies may be more skeptical of U.S.-led nonproliferation efforts—especially as they find their own security, sovereignty, and territorial integrity threatened by the Trump administration. This dynamic was already apparent during the Biden administration, even as the whole of the U.S. government led by the National Security Council and the State Department worked overtime to telegraph to European capitals that “America is back.” Skeptical of Biden’s efforts to turn back the clock on a host of issues, European counterparts frequently asked U.S. officials whether they could guarantee that the next administration would not leave negotiated agreements. The administration could not provide such assurances. This led even the U.S.’s closest allies to adopt the same talking points as its adversaries: Why should anyone strike a deal with one administration only to have it torn up by the next? 

Multilateral negotiations remain a superior format to address proliferation, but they are increasingly difficult to execute due to their length and complexity. Multilateral negotiations allow partners to serve as force multipliers for one another—using both their sticks and carrots in a way that complements what each actor can threaten and offer. Because their negotiations require more concessions to build consensus, and there are several parties that sign on, their resulting agreements tend to be more stable. 

Conversely, bilateral negotiations are easier to complete in a timely manner but are also more likely to fall apart once administrations change. This is because once one party withdraws from the deal or violates its terms, there are no third parties to maintain it. For example, Iranian leaders decided not to kill the nuclear deal by withdrawing from it, despite the United States’ exit, because they expected the remaining parties to continue upholding their end of the agreement. Of course, if the United States threatens to levy sanctions against parties that uphold an agreement it has left, other capitals’ ability to maintain compliance with a deal will inevitably be challenged. 

Second, Washington must adapt to shorter timelines when building the architecture for nonproliferation policies. In previous decades, including at the height of arms control, presidents did have to contend with the possibility that they wouldn’t have a second term or that they would run out of time if they were already in their second term. However, policymakers from one administration could at least bank on their successors’ willingness to carry their work through. At a minimum, there was an expectation that agreements would be preserved from administration to administration as doing so was judged to serve the national interest. 

Today, that’s no longer the case. Even agreements that clearly serve national security and ratified treaties appear vulnerable to withdrawal. Both multilateral and unilateral sanctions require time to exert pressure. But multilateral sanctions may no longer constitute a realistic pathway for current and future administrations. Unilateral sanctions may be less effective, but they can be imposed more quickly. The State and Treasury Departments can quickly move to begin building pressure by imposing sanctions while they engage other nations to do the same. Utilizing targeted authorized and public disclosures of intelligence is an important tool that helps garner international support for U.S. policies and develop specific counterproliferation actions, including sanctions packages. But U.S. intelligence won’t be viewed without skepticism in light of its politicization in recent months, as was the case in the lead-up to the Iraq war.

Each president must either ensure that there’s bipartisan support for an agreement—that is rarely ever the case today—or focus on quicker, more targeted deals. To take the example of Iran’s nuclear program again, an administration may consider dedicating its efforts to the enrichment program or to monitoring and verification as informed by the intelligence community and advised by the Energy and State Departments, without tackling the entirety of the nuclear program. It would then offer much narrower sanctions relief to the other side, such as a specific commercial transaction. Of course, this approach would come with its own shortcomings, as it both strips the parties of some bargaining leverage and falls well short of a more comprehensive solution required to effectively diminish the threat of a nuclear weapon. 

As the Iran case demonstrated in the lead-up to the JCPOA, such an approach would also risk garnering significant domestic criticism. Yet, if the United States can’t engage in prolonged negotiations and no administration has enough time for the parties to reap the fruits of their labor, then shorter, simpler, and less comprehensive solutions may be the only way forward short of giving up on preventing proliferation. There’s a risk that presidents may try to rush into agreements to beat the clock. But that’s also not wise, as Americans can seldom compete for time with adversaries who are not often bound by the same political calendar as we are. Further, rushing to a deal may lead to suboptimal agreements that exacerbate problems rather than remedy them. 

Lastly, the United States is likely to face allied proliferation, including from within NATO, in the years to come. This is a different challenge from the one American policymakers have encountered in recent years, as officials mostly tackled the challenge of adversary proliferators. Countering proliferation by allies would require different tools from those Washington has levied against adversaries. For example, if South Korea, which houses American forces on its soil and is a treaty ally of the United States, were to weaponize its nuclear program, sanctions and the threat of force would likely not yield the same results as they would with an adversary. What’s more, such actions would negatively impact U.S.-South Korea relations, including America’s ability to rely on a key ally in the Indo-Pacific region, potentially handicapping U.S. national security and ability to compete with China. The solution is clearly not to allow allies and partners to develop nuclear weapons, as this would undercut U.S. national security, global security, and regional stability. But it does require rethinking the toolkit in ways that American policymakers haven’t had to do in a long time. 

Barring structural changes to U.S. policymaking or a rejuvenated Congress asserting itself, the current toolkit, as it was conceived after World War II, is no longer adequate to tackle the most significant national security challenges that the United States will likely face in the years to come. If the U.S. is to prevent proliferation by friends and foes, it needs to recalibrate its toolkit to adapt it to today’s political reality, wherein administrations have less time and leverage to enact their policy priorities. These changes won’t lead to optimal outcomes as they may once have, but where nuclear warfare is concerned, America can’t afford to let the perfect be the enemy of the good.