Trump, Deterrence, and the Erosion of Nuclear Restraint

By Ramesh Jaura*

This article was first published on https://rjaura.substack.com

BERLIN | 16 November 2025 (IDN) — Ahead of his meeting with Chinese President Xi Jinping on 30 October at Gimhae International Airport in Busan, South Korea, U.S. President Donald Trump declared he had ordered the resumption of U.S. nuclear testing. His statement shattered more than three decades of restraint. “I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis,” he wrote on social media. He argued that rival powers, such as Russia and China, were already advancing their own programs.

For nearly thirty years, Nevada’s desert had remained silent since the United States conducted its last nuclear explosive test in 1992. Beneath that silence lay the legacy of 1,032 detonations that once lit up the American night sky. Trump’s declaration, whether rhetorical or real, revived the most haunting question of the nuclear age: Can the mere threat of using nuclear weapons ever be lawful?

On 2 November, Energy Secretary Chris Wright clarified that the administration was not planning explosive tests. “These are not nuclear explosions,” he said. “These are what we call non-critical explosions—system tests.” Yet the announcement itself carried immense symbolic weight. Even without detonation, signalling readiness to test conveyed a threat of force. The return to nuclear brinkmanship, Kimiaki Kawai argues in Nuclear Deterrence and the Threat of Force, transforms deterrence from policy into ongoing coercion, which may already violate the United Nations Charter.

Kawai’s legal analysis centres on this contradiction: deterrence, though framed as defence, is built on a standing threat of annihilation. Trump’s 2025 statement exposed the thin line between demonstration and intimidation. His words suggested not scientific prudence, but a deliberate assertion of will. As Kawai — professor at Research Center for Nuclear Weapons Abolition, Nagasaki University — observes, nuclear deterrence “is fundamentally based on the threat of using nuclear weapons.” Therefore, it risks falling under the UN Charter’s prohibition on threats of force.

The Absolute Weapon

The notion that nuclear weapons preserve peace by threatening catastrophe dates back to the bomb’s earliest theorists. Following the bombings of Hiroshima and Nagasaki in August 1945 U.S. strategist Bernard Brodie wrote in “The Absolute Weapon: Atomic Power and World Order” that nuclear arms had altered the meaning of war: “The chief purpose of our military establishment must be to avert wars rather than to win them.” The bomb, he argued, was valuable not in its use but in the fear it inspired.

Yet as Kawai reminds us, early U.S. planners still saw atomic bombs as tactical weapons. A 1945 Joint Chiefs of Staff report even proposed targeting “population centres” to break morale—a view that violated international humanitarian law’s rule of distinction.

This duality—Brodie’s deterrence versus the Yales University’s William Borden’s war-fighting—shaped U.S. nuclear doctrine for decades. Out of this grew the Cold War’s grim equilibrium, known as Mutual Assured Destruction (MAD). Later theorists, such as Glenn Snyder and Robert Jervis, defined deterrence as preventing unwanted action by making nuclear retaliation seem credible. As Kawai writes, its essence lies not in use but in “the credible possibility of use.” Peace was thus sustained by fear—a paradox that, by the 21st century, continues to haunt policy.

Law versus Fear

The atomic bomb’s first mushroom cloud revealed both scientific triumph and moral collapse. That same year, 1945, the UN Charter outlawed both the use and the threat of force. Yet the global peace that followed depended on precisely that: the constant threat of nuclear use. The International Court of Justice (ICJ) in The Hague addressed this tension in its 1996 Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons. It found that both threat and use would generally violate international law. However, it left a narrow exception for “an extreme circumstance of self-defence” where a state’s survival is at stake.

Kawai views ambiguity as a legal gap that allows deterrence to persist. Article 2(4) of the UN Charter prohibits the threat or use of force against the territory or independence of any state; therefore, if force is illegal, threatening it is also illegal. Kawai argues deterrence is unlawful, since any nuclear use would breach humanitarian rules of proportionality—military action must match the threat—and distinction—attacks must only target military, not civilians. “Nuclear weapons have catastrophic humanitarian consequences,” he writes. “Relying on potential nuclear use may not meet legal standards.” If so, deterrence—even without launch—is a banned threat.

Desert Rock I, Buster-Jangle Dog, November 1, 1951

The Trump Doctrine

When Trump revived nuclear testing rhetoric, he intended to send a signal, not discuss engineering. His words echoed his 2017 threat to unleash “fire and fury like the world has never seen” on North Korea and his later claim of wanting to build “ten times more nuclear weapons” than the U.S. possessed. In Kawai’s view, such language is core to nuclear signalling. Its effectiveness depends on the perceived credibility of the threat. In 2025, Trump sent an unmistakable message to China and Russia: America would not hold back if others advanced. But this show of strength invited instability. Relying on threats over principles weakened the United States’ moral and legal standing.

Trump’s announcement provoked swift reactions abroad. The Kremlin warned that if any state abandoned the moratorium on nuclear testing, “Russia will act accordingly.” Beijing offered no formal statement but interpreted the move as strategic pressure ahead of Trump’s meeting with President Xi Jinping.

Across Europe, officials voiced concern that even non-explosive testing could erode the taboo against nuclear detonations. They also worried it could complicate NATO’s posture.

Japan’s hibakusha groups (survivors of the atomic bombings of Hiroshima and Nagasaki) condemned the rhetoric outright, warning that “the shadow of Hiroshima still falls over every new threat.”

Non-nuclear states and civil society actors were equally alarmed. The Non-Aligned Movement called any return to testing “a setback for humanity.” Disarmament organisations warned that ambiguity itself was destabilising. As the Federation of American Scientists noted, the uncertainty surrounding Trump’s words “exacerbates tensions” and may encourage others to respond in kind.

Kawai’s analysis captures this danger: coercive signalling is reciprocal. Threat begets counter-threat, creating what he calls a “threat-based security hierarchy” that constrains non-nuclear states and perpetuates dependence on nuclear protection.

Soka Gakkai International (SGI) — where Kawai was the Program Director for Peace Affairs and the Director for the Peace Committee of Soka Gakkai (Japan) — did not directly respond to Trump’s latest move, but its statements and activities reflect a stance that opposes the U.S. President’s rhetoric and policies. The organisation, headed by Minoru Harada, has called for international cooperation, dialogue, and de-escalation, particularly in contrast to an emphasis on unilateralism and military buildup.

The same concern motivated the manifold efforts to build peace and renounce war initiated by his mentor SGI President Daisaku Ikeda (1928–2023)—from his visits to countries in Asia devastated by Japanese brutality to his efforts to rid the world of nuclear weapons, and his contribution of annual peace proposals over a 40-year period.

From Nevada to The Hague

A U.S. return to testing—even a symbolic one—would challenge decades of legal and moral restraint. It would contradict the spirit of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which the United States signed but never ratified, and the Treaty on the Prohibition of Nuclear Weapons (TPNW), which bans not only the use but also the threat of use of nuclear weapons under any circumstances. Kawai describes the TPNW as a landmark: “It provides a clear normative stance against general deterrence.” For him, the Treaty’s Article 1(1)(d)—which prohibits any threat to use nuclear weapons—closes the gap left by the UN Charter, categorically outlawing nuclear intimidation.

Although no nuclear-armed state has joined, the Treaty’s normative power is growing. Over ninety non-nuclear nations have ratified it, reflecting an emerging opinion juris that the possession of nuclear weapons itself constitutes an ongoing threat to humanity. “The TPNW marks a shift,” Kawai writes, “from accommodating nuclear threats to challenging their legality.” In this light, to test is to confess—to admit that deterrence depends on readiness to destroy.

The Erosion of Legal Boundaries

In 2022, Russia’s invasion of Ukraine and President Vladimir Putin’s nuclear warnings revealed how fragile the nuclear taboo has become. His statement that any interference would bring “consequences such as you have never seen in your history” exemplified what Kawai terms coercive signalling. Trump’s earlier brinkmanship paved the rhetorical ground for such acts. Both leaders blurred the distinction between deterrence and intimidation, treating nuclear arsenals as instruments of political leverage rather than ultimatums.

Kawai cautions that even so-called “general deterrence,” which names no adversary, is never neutral. It always implies potential targets. By sustaining vast arsenals and doctrines of first use, nuclear states maintain a structural inequality that limits the autonomy of others. In East Asia, alliances under the U.S. nuclear umbrella constrain local policy. In Europe, NATO’s deterrence logic binds members to an order built on fear. “Nuclear deterrence,” Kawai concludes, “is not a neutral condition but a form of global coercion.”

The Ethics of the Unthinkable

Behind legal doctrine lies an enduring moral truth: deterrence rests on the credible threat of mass death. As Michael Walzer wrote, nuclear weapons are “designed to kill whole populations,” and their power to deter “depends upon that fact.”

Kawai underscores this paradox with Brodie’s old analogy: “You don’t shoot a rabbit with a gun made to shoot elephants.” The bomb’s very inhumanity is its utility. In the Trump era, that moral absurdity re-entered global discourse. His withdrawal from the INF Treaty, hesitation on New START, and emphasis on tactical nuclear roles all blurred the line between threat and potential use. Each action reaffirmed that deterrence is a continuous rehearsal. Legally, Kawai argues, such postures “amount to a threat of force as prohibited by Article 2(4) of the UN Charter and are therefore unlawful.” Ethically, they represent a bargain with annihilation. Peace is purchased through fear.

The Return of the Test Era

The Trump administration justified its testing proposal as a way to ensure stockpile reliability and pressure adversaries into negotiating. Yet critics, such as former Energy Secretary Ernest Moniz, warned that “a return to testing would send exactly the wrong signal” and encourage others to follow. The Federation of American Scientists cautioned that even a single low-yield test could unravel decades of restraint.

Under Kawai’s legal interpretation, such a test—intended to reinforce deterrence—would constitute a communicative act of coercion, not mere experimentation. Because deterrence depends on credibility, every display of readiness is, in itself, a threat. In this way, testing collapses the distinction between legality and intimidation.

The Law’s Last Frontier

Since the ICJ’s 1996 opinion, no international court has revisited the legality of nuclear threats. Yet the landscape has shifted. The TPNW now stands as a counter doctrine, rejecting the logic of fear that underpins the doctrine of deterrence. Kawai notes that the Treaty’s norm-setting function “delegitimises both immediate and general deterrence” and forces a choice between two paths: one that tolerates nuclear threats, and one that prohibits them.

This divide mirrors the world’s moral geography. To non-nuclear states, deterrence is a pathology— a critical perspective arguing that deterrence policies are a form of societal or political sickness, often rooted in the flawed idea of individual dysfunction rather than social and economic factors. To nuclear states, a pillar of security. Trump’s testing rhetoric laid bare that fracture—a contest between security through fear and security through law.

The Future of Deterrence

President Joe Biden quietly shelved Trump’s testing idea but retained deterrence as a doctrine. His 2022 Nuclear Posture Review reaffirmed that nuclear weapons “continue to play a unique role in deterring strategic attacks.” Across Ukraine, Gaza, and the Taiwan Strait, the same logic endures. As Kawai writes, “the future of the legal order depends not only on interpreting norms but on choosing which normative trajectory to embrace: one that tolerates nuclear threats, or one that prohibits them.”

The world again stands between Nevada and The Hague—between force and law. Trump’s proposal exposed deterrence’s fatal paradox: every nuclear power claims its arsenal is defensive, yet each maintains it through the threat of annihilation. The TPNW offers a different imagination: security without fear. It remains aspirational, but as Kawai reminds us, both law and deterrence begin in the mind—in what humanity dares to imagine. Trump’s test rhetoric, echoing across deserts and courtrooms, is a reminder that peace sustained by fear is peace perpetually at risk.

About the author: Ramesh Jaura is a journalist with 60 years of experience as a freelancer, head of Inter Press Service, and founder-editor of IDN-InDepthNews. His work draws on field reporting and coverage of international conferences and events. [IDN-InDepthNews]

Original link: https://rjaura.substack.com/p/the-return-of-the-bomb

President Donald Trump with Chinese President Xi Jinping, Source: White House.

Desert Rock I, Buster-Jangle Dog, November 1, 1951