▶️ The international nuclear order, based on the NPT, has been under stress as great power competition intensified since the late 2010s and the U.S.—once the foremost champion of nuclear disarmament and nonproliferation —has retreated from global governance.

▶️ President Trump is known for his disregard for the NPT, desire to achieve nuclear superiority over nuclear equilibrium and strategic stability, and reluctance to extend the U.S. nuclear umbrella to non-nuclear allies. Thus he is perceived as a serious risk factor to the already fragile international nuclear order.

▶️While President Trump’s willingness to engage with Kim Jong Un may help ease military tensions on the Korean Peninsula, his indifference to the complete denuclearization of North Korea could further stimulate South Koreans’ demands for nuclear armament.

Global Nuclear Governance at Risk

The global nuclear order, built upon the Nuclear Non-Proliferation Treaty (NPT) with the consent of both nuclear-weapon and non-nuclear-weapon states, faces unprecedented strain as their long-held consensus on the values of nuclear disarmament and nonproliferation fades away. Once upheld by U.S. leadership, the global nuclear disarmament and nonproliferation regime has eroded in recent years, with troubling implications for not only the nuclear nonproliferation but also nuclear use risks, both intended and unintended.

The post-Cold War trends toward nuclear disarmament and nonproliferation under the U.S.-led unipolar international system came to an end when U.S. hegemony declined, China rose, and Russia returned in the 2010s. Seeing the world moving in the wrong direction—toward arms races and military conflicts—United Nations Secretary-General António Guterres published Securing our Common Future: An Agenda for Disarmament in 2018. This booklet raised national and international factors leading to an intensified (nuclear) arms race and proliferation as follows:

First, we are on the brink of a new cold war. The new cold war is increasingly marked by unrestrained arms competition, interference in domestic political processes, and the increasing pursuit of malicious and hostile acts. Multilateral disarmament negotiations have been deadlocked for over two decades, and bilateral negotiations have been halted.

Second, regional conflicts have become more frequent and complex. The re-emergence of strategic tensions between major powers is taking place alongside a resurgence of civil conflicts. Today’s armed conflicts are more protracted, more lethal for civilians, and more prone to regional rivalries and external intervention, including by major powers.

Third, the new world order is more complicated than the previous bipolar world order. The international system is becoming multipolar, entailing multiple spheres of power and influence, a growing multiplicity of interests, conflicts, and asymmetries. The diffusion of power has resulted in a multiplicity of regional arms races.

Fourth, increasing militarization is everywhere. Global military spending has more than doubled in inflation-adjusted dollars since the end of the Cold War. Unrestrained military modernization—both nuclear and conventional—is creating distrust, worsening tensions, and making peaceful resolutions to conflicts harder to achieve.

Fifth, eroding respect for international norms is weakening our international political and security institutions. Many of the fundamental principles developed over the past century to preserve peace and safeguard humanity are under strain. Some countries have unilaterally resorted to the use of force, both when it served their interests and when international institutions failed to meet their responsibilities.

Sixth and lastly, the post-Cold War generation’s indifference to existential risks posed by nuclear weapons has weakened advocacy for nuclear disarmament and nonproliferation.

The Doomsday Clock, published annually by the Bulletin of the Atomic Scientists, symbolizes the nuclear danger threatening humanity. In 2024, the Doomsday Clock reached a historic proximity to midnight or nuclear armageddon. Nuclear arms races among great powers, proliferation risks in the Middle East and Northeast Asia, and heightened risks of nuclear use, both intended and unintended, all contributed to this unprecedented warning for humanity’s survival.

The Second Trump Presidency’s Effects

During his first presidency, President Donald Trump displayed not only his ignorance about the deterrent role of nuclear weapons due to their mass destructive power but also his disregard for the values of nuclear disarmament and nonproliferation for world peace. He rejected the traditional bipartisan nuclear policy of nuclear nonproliferation and the limited security role of nuclear weapons.

In 2016, then-Republican nominee Trump reportedly asked “Why do we make nuclear weapons if we wouldn’t use them?” In early 2018, President Trump threatened North Korean leader Kim Jong Un, stating, “I have a nuclear button, much bigger and more powerful than his, and my button works.” Whe North Korea made nuclear threats, Trump responded “they will be met with fire and fury like the world has never seen.”

Alarmed by the danger of these reckless remarks, a group of 17 former nuclear weapon launch officers wrote an open letter to Congress in 2018, claiming that President Trump “poses a clear and present danger to the country and the world.” Claiming to achieve nuclear superiority, Trump withdrew from the INF Treaty, the Iran nuclear deal (JCPOA), and the Open Skies Treaty. He also refused to extend the New START (Strategic Arms Reduction Treaty).

As Trump enters his second term, concerns are growing about the future of the already debilitated NPT regime. Trump has made clear that his foreign and security  nuclear policy would serve to fulfill his campaign slogans “Make America Great Again (MAGA)” and “peace through strength.”

He emphasized the central role of nuclear weapons in U.S. security policy, the supremacy of its nuclear forces over competitors, the modernization of the nuclear triad, and the development and deployment of intermediate missiles and tactical nuclear warheads. Trump’s preference for unilateralism over multilateralism, as well as his focus on strategic superiority rather than strategic equilibrium, bodes ill for the future of the NPT and the New START, the only remaining major nuclear disarmament treaty set to expire in 2026.

How would Trump’s nuclear policy affect regional politics? In Northeast Asia, Trump has belittled the long-standing alliance with South Korea and demanded South Korea pay up to $10 billion—nine times the current cost-sharing expense—to host U.S. forces.

Trump is also suspected of pursuing “nuclear disarmament” negotiations with North Korea to freeze its nuclear arsenal rather than pursuing “complete denuclearization.” Such moves could push South Korea, threatened by Trump’s possible withdrawal of U.S. forces and North Korea’s expanding nuclear arsenal, to pursue its own nuclear armament. In addition, Trump’s plan to deploy intermediate nuclear-capable missiles in East Asia would likely make China further accelerate its nuclear and missile capabilities.

Trump’s return could also destabilize nuclear politics in the Middle East. Trump would likely refuse to re-enter the JCPOA, which he exited in 2018, and resume the “maximum pressure” campaign for more Iranian concessions. This approach, however, may accelerate Iran’s enrichment activities and increase regional military tensions. Iran’s nuclear activities may invite Israeli military strikes to destroy the former’s nuclear facilities. They may also trigger Saudi Arabia’s nuclear development programs to counter Iran’s nuclear capabilities. In this case, the entry of Iran as the ninth and Saudi Arabia as the tenth nuclear-armed state into the nuclear club is not unimaginable.

In summary, President Trump’s second term would likely continue to deviate from the bipartisan tradition of nuclear disarmament and nonproliferation through the NPT and bilateral disarmament treaties. Guided by his convictions of “peace through strength” and “MAGA,” Trump would reverse recent global trends of de-emphasizing the role of nuclear weapons in security policy, avoiding nuclear arms races, suspending nuclear tests, and reducing nuclear risks.

After decades of nuclear arms races and proliferation, humanity came to senses that a nuclear war would bring about the extinction of all life on earth and began the processes of nuclear disarmament and nonproliferation for a nuclear-free world. In the current post-post-Cold War era, nuclear arms races and proliferation have returned as great power politics and history return. A second Trump presidency would accelerate the reversal of these nuclear disarmament and world peace trends. We may once again find ourselves living in a dangerous world of nuclear war risks—until humanity comes to its senses again.

Thumbnail photo usage rights: Public Domain