Ramesh Thakur presents a strong case for challenging the Trump administration’s decision not to recertify the Joint Comprehensive Plan of Action (JCPOA). I’m in broad agreement with the points that he makes. His concluding thought about removing the requirement for recertification suggests a good path forward out of a potential disaster in which the US faces not only an aggressive and unpredictable nuclear-armed North Korea, but an Iran slipping back towards nuclear ambitions.

However, Ramesh’s fifth and sixth justifications for opposing President Trump’s stance in fact highlight critical weaknesses with the JCPOA, and expose the reality that it’s based on a strategy of hope. He states: ‘The JCPOA brought a 15-year respite from the threat of an Iranian bomb. The focus in this grace period should be to ensure Tehran’s full implementation and to change its incentive structure against nuclear weaponisation’, and he then notes that ‘The JCPOA gives political cover to moderates in Iran. An Iran re-engaged with the international community will reinvigorate a growing middle class and could give ballast to moderation and stability in Iran and the Middle East.’

The key challenge is how to achieve those goals. The main risk with the JCPOA is that it ‘sunsets’ in the 2026–2031 period—a mere 10 to 15 years from now. At that point, most restrictions are lifted (though IAEA monitoring will continue for an additional period), which means that Iran could, if it chose to do so, resume its path towards nuclear weapons acquisition. Iran can also exploit the letter of the agreement to make progress in key areas such as centrifuge technology, accelerating a breakout when the time is right. A legitimate question to ask is whether Iran may circumvent the JCPOA over time.

It’s also important to note that, in the interim, Iran will have benefited from the restoration of billions of dollars in funds previously withheld through sanctions, and it would be free in 2020 to begin acquiring advanced military capabilities and in 2023 to develop long-range ballistic missiles. That would imply an Iran that is militarily strong with advanced long-range weapon systems by the middle of the next decade.

Certainly the JCPOA buys the world time. Without it, Iran would rush to a nuclear-weapon capability now, as Ramesh notes. His analysis of US choices in that scenario—either accept Iran as a nuclear weapons state or go to war—is convincing. But lifting sanctions against Iran under the JCPOA doesn’t guarantee that a future Iranian regime won’t decide to pursue nuclear capabilities once the deal sunsets.

Furthermore, there’s no evidence that the Iranian state will shift its broad foreign policy objectives in a direction that’s more focused on cooperation and engagement with the region, and with the broader international community, and in doing so, preclude a perceived need for Iranian nuclear weapons in the future. Iran has demonstrated a willingness to intervene in conflicts in Iraq, Lebanon, Syria and Yemen to assert its influence along two corridors to the Mediterranean Sea. Iran also poses a direct challenge to Arab Gulf states and, of course, to Israel.

The deal, as it stands, is probably the best option at the moment to prevent an Iranian nuclear weapon in the next 15 years, but it shouldn’t be seen as a panacea to all the challenges posed by Iran, and it most certainly doesn’t prevent a future Iranian regime from emulating North Korea’s actions to test the resolve of the US and its partner. The North Koreans withdrew from the Nuclear Non-proliferation Treaty in 2003, after almost 10 years of supposed arms control cooperation under the 1994 Agreed Framework.

The way to avoid history repeating itself is to ensure that Iran is made aware of the costs of such a breakout through a mix of dissuasion and deterrence. In terms of dissuasion, inducements provided through careful economic and diplomatic engagement need to be complemented by a US–EU agreement for effective coordination in rapidly imposing sanctions in the event of an Iranian nuclear breakout. Military cooperation between NATO and the Gulf Cooperation Council could help to counter-balance Iran’s growing influence. Establishing deterrence by denial through NATO and regional ballistic missile defence system needs to be a priority. Existing sea- and land-based missile systems such as the European Phased Adaptive Approach employing systems like Aegis Ashore would make it more difficult for a future nuclear-armed Iran to coerce its neighbours. Missile defence also needs to be supported by non-nuclear prompt-strike capabilities that could threaten Iranian ballistic missiles potentially carrying nuclear or other warheads. New technologies such as hypersonic cruise missiles would fit that role nicely, and are likely to be emerging as possible options by the mid- to late 2020s. Finally, the US, UK and France need to think about the role nuclear deterrence can play in discouraging an Iranian nuclear breakout.

The objective shouldn’t be to replace the JCPOA but to mitigate risks after the Iran deal sunsets in the next decade, and to make an Iranian nuclear breakout at that time an unappealing and costly option for Tehran. This approach of generating greater cost for Iran if it chooses to challenge nuclear non-proliferation must be matched at the same time by political and economic inducements that help moderates in Iranian politics reinforce their power.