One year ago, on 8 May 2018, President Donald Trump announced that the United States would cease compliance with the Joint Comprehensive Plan of Action (JCPOA), the nuclear agreement struck in July 2015 by the United States and Iran, along with China, France, Germany, Russia, the United Kingdom and the European Union.

President Trump has argued that the JCPOA’s provisions are insufficient to block Iran’s progress towards a nuclear weapons capability, do not address Iran’s expanding missile arsenal and do nothing to counter Iran’s activities in the Middle East. He maintains that a strategy of ‘maximum pressure’ is the only way forward and has consequently re-imposed all the US sanctions that were suspended under the deal, including measures targeting foreign companies doing business with Iran (so-called secondary sanctions).

President Trump’s concerns are not entirely misplaced. Withdrawing from the deal, however, will hardly contribute to achieving any of his stated objectives. In fact, his decision has been harmful in several respects.

First, it has undercut global non-proliferation efforts. The JCPOA is a technically sound agreement that has established significant constraints on Iran’s ability to develop a nuclear weapons capability. As certified by the International Atomic Energy Agency (IAEA), the UN nuclear watchdog, and publicly acknowledged by top officials from the US intelligence community, Iran has continued to comply with the deal. However, President Hassan Rouhani’s announcement that Iran is ready to restart certain activities prohibited by the JCPOA shows that, following the US withdrawal, the benefits to Iran of staying in it diminish by the day. If Tehran restarts the full nuclear programme and limits the IAEA’s inspection powers, that would leave only far weaker mechanisms for monitoring its work, including the work reflected in the nuclear archive that Israel claims to have seized from Iran. Other states in the region – notably Saudi Arabia – might be tempted to emulate it and engage in a regional nuclear arms race.

Second, President Trump’s decision has undermined the value of multilateral diplomacy. The JCPOA is a significant instance of effective multilateralism and successful diplomacy, involving countries with very different foreign policy outlooks such as the US and its European allies, Russia and China, and Iran itself. Whereas sanctions coupled with dialogue have proved to be effective in several international crises, the US choice of ‘maximum pressure’ over compromise devalues diplomacy as an effective way to address international disputes among rival states.

Third, the decision has weakened international law and institutions. The JCPOA derives its legitimacy from the Nuclear Non-Proliferation Treaty, which bans Iran from ever seeking a nuclear weapons capability, and its authority from the United Nations Security Council, which has endorsed the deal through its Resolution 2231. By reneging on US commitments without proper cause, Washington has conveyed the message that international obligations can be disposed of at will.

Fourth, it has harmed transatlantic solidarity. The JCPOA was the culmination of over thirteen years of hard, unremitting transatlantic coordination. By pulling out from it and, worse still, by threatening to punish EU companies and banks for doing business with Iran, President Trump has shown utter disregard for Europe’s foreign policy interests and eroded trust in the transatlantic partnership.

Fifth, it has contributed to exacerbating regional tensions. The JCPOA has removed the imminent prospect of a nuclear-capable Iran from a regional landscape deeply fraught with geopolitical tensions. By replacing it with a strategy of ‘maximum pressure’, the US has galvanised Iran’s rivals and reduced the appeal of compromise solutions in Tehran. If Iran leaves the JCPOA, there will be far fewer diplomatic avenues to contain the risk of a military escalation that would plunge the region into further conflict.

Sixth, President Trump’s decision has inflicted undue pain on the Iranian population, whom he claims to support. The JCPOA was supposed to end Iran’s economic isolation in exchange for strict and verified limitations on its nuclear activities. By re-imposing sanctions with extraterritorial effects, the US has scared companies and banks around the world into reducing, ceasing or not starting business with Iranian counterparts. Ordinary Iranians have seen living standards decrease because of a combination of inflation, higher costs for imports, scarcity of available goods (including food and medicine), and the impossibility of finalising transactions that were started before the re-imposition of sanctions.

The JCPOA is doing what it was designed to do: preventing Iran from getting a nuclear weapon. As such, the deal is too important to be allowed to die. Although all remaining parties to the JCPOA say they are committed to the agreement, current efforts to sustain it have not been enough to guarantee its survival.

Europeans should be applauded for the implementation of a Special Purpose Vehicle, called INSTEX, to help facilitate humanitarian trade. However, they should do more to ensure businesses have the clarity they need to conduct trade and should speed up the participation of other countries in the special vehicle. Europe should work to establish another special purpose vehicle expanding the scope of trade to include oil imports from Iran, again open to participation by other countries. Europe should also deepen its technical and political consultations with Iran to reduce risks and build resilience on a range of topics including regional flashpoints and disaster relief.

Overall, JCPOA supporters across the world should increase coordination to make sure that US sanctions do not hamper the economic stability and technical nuclear cooperation Iran needs to comply with the deal.

Most importantly, JCPOA supporters in Europe and elsewhere should re-articulate the merits of the agreement to various US audiences – in the administration, Congress, the expert community and media – so it is clear that the only way to reap the full benefits of the JCPOA and build upon it is for the US to rejoin it.

A US return to the JCPOA would help contain the negative consequences mentioned above. It would also recreate a more cohesive international coalition applying pressure on Iran to curb activities – specifically its development of ballistic capabilities and support to its proxies – that contribute so much to instability in the region. That pressure would then be combined with a credible diplomatic attempt to lay the groundwork for détente and lead to a regional initiative on missile threats and an intra-regional dialogue on a security architecture for the Gulf.

All of this stands a much better chance of success if the US reconsiders its approach to the JCPOA. Much as Europeans spearheaded the process that eventually led to the agreement, so they could lead the way on any future diplomatic initiative with Iran. But for multilateralism to be effective, international law and agreements must be respected.

The signatories of this Joint Call have signed it in their personal capacity. The opinions expressed in the text do not reflect the position of their institutions of affiliation.

Nathalie Tocci | Director, Istituto Affari Internazionali – IAI (Rome)

Des Browne | Chair, European Leadership Network – ELN (London)

Adam Thomson | Director, European Leadership Network – ELN (London)

Esfandyar Batmanghelidj | Founder, Bourse & Bazaar (London)

Steven Blockmans | Head of EU Foreign Policy, Centre for European Policy Studies – CEPS (Brussels)

Ian Bond | Director of Foreign Policy, Centre for European Reform – CER (London)

Ondrej Ditrych | Director, Institute of International Relations – IIR (Prague)

Thanos Dokos | Director General, Hellenic Foundation for European & Foreign Policy – ELIAMEP (Athens)

Michel Duclos | Special Advisor, Institut Montaigne (Paris)

Thomas Gomart | Director, Institut Français des Relations Internationales – IFRI (Paris)

Charles Grant | Director, Centre for European Reform – CER (London)

Mark Leonard | Co-founder and Director, European Council on Foreign Relations – ECFR (London)

Pol Morillas | Director, Barcelona Centre for International Affairs – CIDOB (Barcelona)

Robin Niblett | Director, Chatham House (London)

Charles Powell | Director, Real Instituto Elcano (Madrid)

Laura Rockwood | Executive Director, Vienna Center for Disarmament and Non-Proliferation – VCDNP (Vienna)

Daniela Schwarzer | Director, Deutsche Gesellschaft für Auswãrtige Politik – DGAP (Berlin)

Andris Spruds | Director, Latvian Institute of International Affairs – LIIA (Riga)

Teija Tiilikainen | Director, Finnish Institute for International Affairs – FIIA (Helsinki)

The initiative was coordinated by

Riccardo Alcaro | Research Coordinator, Istituto Affari Internazionali – IAI (Rome)

Shatabhisha Shetty | Deputy Director, European Leadership Network – ELN (London)