A sense of déjà vu in the US nuclear domain: Trump and the prospective policy shift

Newly in the White House from January 20, Donald Trump will have to make some decisions on nuclear weapons policy in the next four years. What will his second term mean for nuclear disarmament in the US and the world? Military help to Ukraine and the expansion of China’s nuclear arsenal are two of the questions on the agenda.

During Donald Trump's first term, its nuclear policy prioritized the development of new nuclear weapons and increased the role of nuclear deterrence in US military strategy. Additionally, during his tenure, the US withdrew from key arms control treaties, such as the Intermediate-Range Nuclear Forces Treaty, the Open Skies Treaty and the Joint Comprehensive Plan of Action, the ground-breaking nuclear deal with Iran. Today, there remains only one significant arms control treaty linking the US and Russia, the 2010 New START Treaty, which Trump initially refused to extend but which was eventually renewed during the Biden administration.

Throughout the years from 2017 to 2021, Trump introduced sweeping changes that altered the global arms control landscape, and his return to the Oval Office could bring significant shifts in the US nuclear posture, potentially differing from the policies of the Biden administration. This article explores how a new Trump administration could alter US nuclear policy compared to current strategies implemented by Biden and the broader implications for global security.

Notably, it can be said that US nuclear policy is based on three essential components: deterrence, modernization and arms control arrangements, each designed to address evolving security challenges and maintain global stability. Firstly, US policy focuses on maintaining a robust and credible nuclear arsenal to deter nuclear and conventional aggression. Reliance on nuclear deterrence has intensified, especially as rival states such as Russia and China expand their nuclear capabilities. Secondly, modernization efforts are driven by the need to upgrade outdated nuclear systems and to ensure the effectiveness of the nuclear arsenal for technological and geopolitical challenges; the modernization program is expected to cost more than $1.5 trillion over the coming decades. Thirdly, at present, nuclear arms agreements face unprecedented challenges. The weakening of arms control frameworks, the withdrawal of several countries from important treaties and the growth of China’s nuclear arsenal could lead to a multipolar nuclear arms race that would further complicate global security.

The Trump legacy: Confrontation over collaboration

Trump’s approach to nuclear policy during his first administration was marked by confrontation and skepticism towards multilateral agreements, especially with nations like Russia. His withdrawal from the Intermediate-Range Nuclear Forces (INF) Treaty in 2018 not only dismantled a cornerstone of Cold-War era arms control but also set the stage for an intensified nuclear arms race with Russia. Similarly, his initial reluctance to extend the New START Treaty—a key bilateral agreement limiting strategic nuclear weapons—strained US-Russia relations.  Although Trump presumes a strong personal relationship with his Russian counterpart, Vladimir Putin, there are challenges inherent in an arms control negotiation between long-standing rivals, steeped in a history of grievances and suspicions.

Furthermore, Trump also adopted an aggressive posture towards North Korea and Iran. On the one hand, his meeting with North Korean leader Kim Jong-un in 2018 generated headlines, but failed to impose significant restrictions in denuclearizing the Korean Peninsula. Instead, Pyongyang used the opportunity to strengthen its nuclear arsenal. On the other hand, Trump’s decision to withdraw from the Joint Comprehensive Plan Of Action (JCPOA), known as the Iran nuclear deal, allowed Tehran to move closer to developing nuclear weapons, raising tensions in the Middle East.

It is clear that Trump’s approach reflected a broader shift in US foreign policy under his administration: a preference for power dynamic and transactional relationships over multilevel collaboration and institutional agreements. As the world is waiting to see what will happen in his second term, the legacy of confrontation over collaboration offers us important insights. It highlights the rises of withdrawing international arms control agreements in favor of unilateral action and the enduring consequences of destabilizing global nuclear agreements. Does Trump returning to power would amplify these tendencies or shift toward a more pragmatic diplomacy?

Biden’s diplomatic deterrence

As opposed to Trump, President Joe Biden's nuclear policy focused on diplomacy and risk reduction. Within weeks of taking office, Biden extended the New START Treaty until 2026, guaranteeing limits on US and Russia deployed nuclear warheads. His administration also engaged in talks with China to manage nuclear risks in an increasingly multipolar world.

In the context of the ongoing conflict in Ukraine, Biden worked to stabilize NATO’s nuclear posture while avoiding escalatory measures that could provoke direct confrontation with Russia, reflecting his focus on maintaining collective security while minimizing risk of nuclear escalation.

Despite these efforts, Biden faced the challenge of maintaining a coherent arms control framework. The suspension of Russia's participation in New START and China's rapid nuclear expansion have complicated the administration's goal of reducing reliance on nuclear weapons. Moreover, in an increasingly fragmented world, Biden's idea of multilateralism faced a number of difficulties in gaining traction; however, he managed to hold talks with countries such as China and Russia, showing his commitment to a strong nuclear deterrent.

Compared with Trump, Biden’s nuclear policy reflected an effort to balance deterrence with diplomacy. While progress was slow, his approach underscored the enduring importance of arms control as a tool for managing nuclear risk and preserving global security.

What to expect from a second Trump administration

Having seen Trump’s first term in office, a re-elected Trump administration is very likely to prioritize nuclear modernization over arms control. According to policy experts, Trump’s administration may abandon formal arms control agreements such as New START, favoring bilateral understandings or informal agreements that align with US strategic interests.  As already discussed, if in the first term Trump pursued nuclear weapon modernization, it is likely that in this second term the administration could accelerate the modernization of the nuclear triad, including intercontinental ballistic missiles (ICBMs), bombers and submarines. It is quite likely that Trump’s return will reignite the nuclear arms race, particularly with China. The expansion of Beijing's nuclear arsenal has already alarmed US policymakers, and Trump could push for measures to counter this growing threat. Such measures could include deploying additional strategic weapons or resuming nuclear testing, actions that would likely destabilize the global security environment.

However, Trump faces a new challenge. Just two months before his potential return to the White House, Biden authorized Ukraine to use long-range US weapons to strike deep inside Russia. This decision marked a dramatic shift in the scope of the Russia-Ukraine war, intensifying hostilities and expanding the battleground far beyond Ukraine’s borders. This could complicate peace efforts and harden Moscow’s demands for more territory taking into account that, on the 1000th day of the war, Putin approved changes to Russia’s nuclear doctrine: any attack from a non-nuclear state, if supported by a nuclear power, will be treated as joint assault on Russia.

Trump has claimed he could broker a peace agreement between Putin and Zelensky within 24 hours, emphasizing his negotiation skills. While specifics are unclear, he has indicated his ability to achieve this swiftly, potentially even before assuming office. Under his ‘America First’ agenda, Trump continues to advocate for a reduced US global presence, raising questions about the future of military aid to Ukraine, which has exceeded $108 billion since Russia’s invasion began in February 2022.

Neither Russia nor Ukraine, not even China know very well what Trump will do after taking office; nonetheless, one certainty is that the future of US foreign policy rests largely in Trump’s hands. On nuclear weapons, Biden leaves Trump with the legacy of allowing Ukraine to use ATACMS missiles on Russian territory. It may be that Trump could reverse these decisions in the first days as president. But he could also decide to maintain such agreements. Whatever path Trump chooses, his return to the office could signal a turning point in US foreign policy—particularly his nuclear doctrine—, one that could refine the balance of power, test old alliances, and reshape the international landscape.