As President-elect Joe Biden and Vice-President-elect Kamala Harris prepare to be sworn in on 20 January, there’s an expectation of US re-engagement with multilateralism and a return to some semblance of normality, stability, continuity and predictability. Exciting days may be behind us and there will be a general sigh of relief around the world for that.

Going by repeated campaign promises and the transition-team website ^[1], among the earliest foreign policy decisions of the Biden administration will be to ‘recommit’ ^[1]to the Paris pact on climate change and ‘restore’ ^[2] the US’s relationship with the World Health Organization in battling the coronavirus pandemic that is now showing the expected winter surge across North America and Europe.

The normative architecture of nuclear arms control comprising various bilateral and multilateral agreements will also be up for reconsideration. Among the easiest decisions should be to extend current agreements that are nearing the end of their shelf lives.

Russia and the US signed New START in Prague in April 2010 and it came into force on 5 February 2011. The treaty reduced each country’s strategic missile launchers by half, limited the numbers of warheads that can be deployed on the missiles, and established an inspection and verification regime to monitor implementation. It has a provision for a one-off extension by five years, but President Donald Trump repeatedly rebuffed Russian overtures to do so. Extending it will help maintain stability and buy time to negotiate a follow-on agreement. Biden and Russian President Vladimir Putin should also discuss additional measures to control new types of strategic offensive arms under development, as well as strategic defensive arms.

A second priority should be to rescind US withdrawals from treaties that were operating largely successfully but that the Trump administration pulled out for short-sighted and extraneous reasons. Three are especially relevant.

On 22 November, six months after serving notice, the US withdrew from the 35-party 1992 Open Skies Treaty ^[3] that was both a symbol of political engagement and a practical contribution to risk reduction. Over the course of its lifespan, the treaty authorised nearly 1,500 missions, including more than 500 flights over Russia as the most overflown and best-monitored country, with every flight muting anxiety about surprise attack. Describing it as ‘One of the pillars upholding international peace and security today’, former US secretary of state George Shultz, former defence secretary William Perry and former Armed Services Committee chair Sam Nunn noted that even during times of tension in Russia–US relations, the treaty helped to ‘preserve a measure of transparency and trust’. They warned in October 2019 that ‘withdrawal would be a grave mistake ^[4]’. Biden would do well to correct the mistake.

Signed in December 1987, the Intermediate-Range Nuclear Forces Treaty was the first nuclear disarmament agreement that prohibited both conventionally armed and nuclear-tipped ground-launched missiles in the 500–5,500 kilometre range. By the implementation deadline of mid-1991, around 2,700 missiles had been destroyed, of which two-thirds were Soviet-made. It made a significant contribution to the security of Europe as the main Cold War front line and helped underpin broader international security for 30 years. When Trump pulled out of it in February 2019, Russia followed suit and the treaty lapsed in August 2019. Because of the potentially destabilising consequences of an arms race involving intermediate-range missiles, it would be good to begin negotiations on restoring the reciprocal restraints while simultaneously exploring practical opportunities to bring China into trilateral frameworks.

The Joint Comprehensive Plan of Action had reversed and mothballed Iran’s suspected nuclear-weapon program. Its resuscitation may prove complicated ^[5] because the politics around it involve Iran and the ayatollahs, Israel, other Arab allies, and weapons of mass destruction. Trump withdrew from the deal in 2018, yet in 2020 bizarrely claimed that the US could trigger reimposition of sanctions on a noncompliant Iran as a party to the JCPOA. Most UN Security Council members rejected the US move. Biden has indicated a desire to return to the deal ^[6], but only if Iran is in compliance with it.

If the domestic US and Middle East regional politics can be taken care of, the legal route to the US returning to the JCPOA is simple enough. Biden could simply revoke Trump’s decisions and actions and return to full compliance with the agreement. A major benefit of this would be to restore US credibility with the European allies and also China and Russia as the original deal-makers and signatories of the P5+1 negotiations that produced the JCPOA, which in 2015 received unanimous endorsement by the Security Council in resolution 2231 ^[7].

Unfortunately, following the US withdrawal, Iran breached ^[8] the JCPOA’s purity and quantitative limits on uranium enrichment. With Trump’s pullout having discredited the accommodationists, there will also be stiff resistance in Tehran to an on-again, off-again relationship with Washington.

The assassination of Iran’s top nuclear scientist, Mohsen Fakhrizadeh, on 27 November, almost certainly by Israel, gives a strong hint of how Biden’s election is already shaking up Middle Eastern affairs. It could embolden Trump to engage in scorched-earth policies in the dying days of his presidency. Iran is left with a lose–lose choice: retaliate against Israeli targets and risk a military strike by Trump and the death of the JCPOA, or do nothing and suffer an erosion of domestic support and a loss of regional prestige.

Iran’s initial response, as reported by the New York Times ^[9], appears to have been to mandate an increase in uranium enrichment to 20%, a move that would ‘give Iran the ability to convert its entire stockpile to bomb-grade levels within six months’.

The most vexed nuclear problem to confront the new administration will be North Korea. Trump’s unbounded faith in his deal-making prowess notwithstanding, he failed to achieve any concrete progress in denuclearisation in return for conferring a degree of legitimacy on the Kim regime as a de facto nuclear-armed state. Biden may have little choice but to live with this reality ^[10]. He could aim for a system of restraint that puts verifiable and enforceable limits on North Korea’s numbers and range of warheads and missiles while reaffirming extended deterrence to reassure Seoul and Tokyo.

Finally, there is unlikely to be any noticeable shift in the US position on the Treaty on the Prohibition of Nuclear Weapons that will enter into force exactly two days after Biden and Harris are sworn in.  But perhaps they could soften the stridency of the opposition that has served to poison the atmosphere ahead of the postponed review conference to mark the 50th anniversary of the Nuclear Non-Proliferation Treaty.

In an address in London in February, Trump’s ranking arms control official Chris Ford was openly contemptuous ^[11] of the arms control community as virtue-signalling nuclear identitarians. An early commitment by the Biden administration to preserve, uphold and further advance nuclear arms control agreements would help to protect the integrity of the rules-based international system with effective multilateralism as a key principle.