The Oxford Essential Dictionary of the US Military defines deterrence as “the prevention from action by fear of the consequences. Deterrence is a state of mind brought about by the existence of a credible threat of unacceptable counteraction.” From this, readers can deduce that deterrence is a state of mind and a product of rational decision-making.

Basing security policy on either of these assumptions is foolhardy. It is challenging to calibrate deterrence. This requires distinguishing enough deterrence, where credible fear of counteraction keeps the peace, from too much deterrence, where credible fear of an opponent’s motives can lead to a preemptive attack.

First, some practical examples. Returning to October 7, 2023, it is possible to say Israeli deterrence failed. Since 1948 Israel has sought to maintain a level of strength and preparedness sufficient to prevent its enemies from planning and executing attacks, using the threat of overwhelmingly force to maintain deterrence against its enemies.

The first major sign of trouble with this approach came in 1968, months after Israel’s defeat of its Arab neighbors in the Six-Day War, when Egypt began preparing a response. This came in October 1973 with Operation Badr, the attack which kicked off the Yom Kippur War. Similarly, Hamas began planning its 2023 attack immediately after a major defeat nine years before in the Gaza War of July–August 2014.

In both cases, deterrence failed years before the actual attacks. Israel’s overwhelming military superiority simply delayed the inevitable response to a situation its adversaries saw as absolutely unacceptable. Israel, overconfident in its deterrent capability, discounted the danger when intelligence assets began to report trouble. Thus, a single-minded reliance on deterrence actually led to future conflict.

So much for recent practice. On the theoretical side, scholars and practitioners alike have sought to chart the proximate triggers of war. The Athenian general Thucydides offered a multi-dimensional explanation in his History of the Peloponnesian War. He believed conflict resulted from three factors: Phobos (fear), kerdos (self-interest), and/or doxa (honor or reputation).

Deterrence, as we have seen, relies on threats of force which induce phobos, and therein lies a huge problem: it ignores the crucial elements of self-interest and honor or reputation. Thucydides named phobos as a principal trigger for conflict, even as definitions of deterrence, the current paradigm for conflict prevention, cite its reliance on instilling phobos. As the French might say, not only does deterrence fail in practice, but even worse, it does not work in theory.

Nuclear Deterrence and Global Devastation 

The shortcomings of conventional deterrence are well documented. Then there is its younger brother, nuclear deterrence. The story there is much simpler. Recent research on nuclear winter has lowered estimates of the megatonnage of nuclear detonations needed to trigger the phenomenon. Significant global effects leading to the starvation of over a billion people could be triggered by the use of as few as one hundred “small” Hiroshima-sized (total 1.5 megatons) explosions over urban targets.

This is extraordinarily bad news for the nuclear weapons priesthood, which has been chanting slogans of escalation dominance in government ears since the 1960s. The only rational nuclear deterrence that can be relied upon, it now seems, is self-deterrence, where a conflict which seems unwinnable by conventional means is now far more likely to appear unthinkable in nuclear terms.

Seeking a Realistic, Effective Alternative

Eliminating all nuclear weapons is clearly a necessary part of the journey towards lasting peace. But focusing on particular weapons is miscasting the problem and thus misunderstanding the nature of the solution. The world needs a transition away from the deterrence-based para bellum paradigm, the idea that achieving peace requires constant preparation for war, toward a new way of looking at conflict. This article proposes a radically different paradigm, Trinitarian Realism, which rests upon three principal assumptions.

First, in a concept borrowed from the Christian Trinity, one’s individual confession (peccavi) is important, but the collective and universal confession (peccavimus) is crucial in international peacebuilding. All need to recognize that each has sinned and fallen short, that no one comes to the table, any table, anywhere, with completely clean hands. Second, readers must truly grasp Carl von Clausewitz’s “remarkable trinity” in war, combining the irrational (war moves a citizenry to violence, hatred, and enmity); the non-rational (commanders face “the play of chance and probability”); and the über-rational (governments attempt to “subordinat[e war] as an instrument of policy”).

This guarantees wholly unknowable results. As Nassim Nicholas Taleb points out, “What is surprising is not the magnitude of our forecast errors, but our absence of awareness of it. This is all the more worrisome when engaging in deadly conflicts; wars are fundamentally unpredictable (and we do not know it).” Finally, that the July 16, 1945, Trinity event at White Sands, New Mexico, the first nuclear explosion, introduced a global catastrophic risk arising from the multiple and wide-ranging ecological effects of nuclear winter.

A transition away from deterrence can begin by not reflexively demonizing anyone with whom there is a serious disagreement. Softening morality projections and focusing judgment on a better understanding of complex collective emotions is also helpful. We can do this with far greater humility, including recognition that we will get our assessments wrong.

Writing of diplomatic historian and Christian apologist Herbert Butterfield, political scientist Paul Sharp provided the bare bones of a three-dimensional replacement for deterrence which we call strategic compassion: “Butterfield’s writings on Christianity and international relations suggest…the moral principles of self-restraint [as antidote for fear/phobos], empathy [honor/doxa] and charity [self-interest/kerdos] upon which an effective diplomacy should be based.”

Finally, we believe that nations must abandon their attachment to nuclear deterrence postures for the reasons outlined above and must accept the eradication of all nuclear weapons—before they eradicate all of us.

Paul Ingram is a Research Affiliate and former Academic Programme Manager with the Centre for the Study of Existential Risk (CSER) at Cambridge University. Edmond E. (Ted) Seay III is a retired Foreign Service Officer with 26 years’ experience in arms control, disarmament, and nonproliferation. His final assignment was as principal arms control advisor to US NATO Permanent Representative to the North Atlantic Council Ivo Daalder.

Deconstructing Deterrence was originally published on Global Security Review.

Throughout his first term, Trump consistently emphasized the importance of nuclear weapons to national security. He viewed nuclear modernization as essential to maintaining military superiority, often stating that the United States must have the strongest nuclear arsenal in the world. In a 2017 interview, Trump said, “We have to be the top of the pack,” signaling his commitment to nuclear dominance.

Trump’s push for nuclear modernization culminated in the 2018 Nuclear Posture Review (NPR), which highlighted the need to revitalize the nuclear triad—comprising land-based intercontinental ballistic missiles (ICBM), submarine-launched ballistic missiles (SLBM), and strategic bombers. The NPR called for developing low-yield nuclear warheads, modernizing aging delivery systems, and investing in new nuclear command, control, and communication (NC3) infrastructure. These initiatives reflected Trump’s belief that a robust and credible nuclear deterrent is the bedrock of national security.

Policies and Actions During Trump’s First Term

Trump’s nuclear policies were characterized by a blend of assertiveness and unpredictability. He withdrew the United States from the Intermediate-Range Nuclear Forces (INF) Treaty, citing Russian violations, and signaled reluctance to renew the New START Treaty without significant changes such as adding China to the treaty. While these actions were criticized by some as undermining arms control efforts, they were consistent with Trump’s view that the United States should not be constrained by treaties that he perceived as one-sided or outdated.

Under Trump, the Pentagon pursued the development of new nuclear capabilities, including the W76-2 low-yield warhead, which was deployed on Ohio-class submarines. This move was intended to provide the US with more flexible and credible deterrence options, particularly against regional adversaries. Trump also supported the development of the Sentinel ICBM to replace the aging Minuteman III.

However, Trump’s approach to nuclear deterrence also included moments of brinkmanship and unpredictability. His “fire and fury” rhetoric toward North Korea and his famous twitter threat that “I too have a nuclear button, but it is a much bigger & more powerful one than his, and my button works!” underscored his willingness to use the threat of nuclear force as a means of coercion.

While these statements alarmed many, they also demonstrated Trump’s belief in the deterrent value of projecting strength and unpredictability. Ultimately, perceptions of Trump’s nuclear rhetoric varied—some saw it as inflammatory, others as necessary to exercise strength and resolve—but the fact remains that during his administration, the US avoided major conflicts.

 The Role of Trump’s National Security Advisors

Trump’s national security advisors played a crucial role in shaping his nuclear policy during his administration and are likely to continue to do so moving forward. Looking ahead, a potential Trump administration is already seeing a contest for top national security positions, with figures like Richard Grenell and Elbridge Colby emerging as frontrunners for the role of National Security Advisor. Grenell is known for his staunch “America First” stance and his confrontational style, which aligns closely with Trump’s preferences. Colby, a former senior Pentagon official, is a strong advocate for focusing military efforts on countering China, potentially signaling a shift in priorities away from Europe.

The selection of these advisors would likely shape Trump’s nuclear policy in significant ways, emphasizing a hardline stance on China, a push for further nuclear modernization, and a continuation of the “America First” doctrine that marked his first term. As Trump’s potential return to the White House looms, the advisors he chooses will play a pivotal role in determining how the US navigates the complex landscape of nuclear deterrence and global security.

What Could a Second Trump Term Mean for Nuclear Deterrence?

If Trump were to return to the White House, it is likely that his administration would continue to prioritize nuclear modernization. The Sentinel program, the development of the Columbia-class submarine, and the enhancement of NC3 infrastructure would likely remain top priorities. Additionally, Trump could seek to further expand the nuclear arsenal quantitatively and qualitatively, potentially fielding new nuclear weapons, such as sea-launched cruise missiles (SLCM) or new low-yield options.

A second Trump term could also see a continuation of his assertive approach to arms control. Trump may push for more stringent terms in any potential arms control agreements, or he could further distance the US from existing treaties if he perceives them as constraining American capabilities. This approach could lead to increased tensions with China and Russia, potentially sparking a new arms race, or it could be the exact prescription required for effective arms control.

At the same time, Trump’s willingness to engage in high-stakes diplomacy, exemplified by his dealings with North Korea, indicates he might pursue similar approaches with other nuclear-armed adversaries. However, the unpredictability that defined his first term could heighten the risk of miscalculation or escalation, especially in nuclear crises, or it could be that it just happens to induce a proper amount of fear that the adversary effectively backs down or ceases operations. Ultimately, Trump’s unpredictability serves as a tool to instill fear and uncertainty in adversaries, keeping them cautious and off-balance.

 Conclusion

 A second Trump presidency could bring renewed momentum to US nuclear deterrence and modernization efforts. Trump’s first term demonstrated a clear commitment to revitalizing America’s nuclear arsenal, recognizing its crucial role in maintaining national security. His administration prioritized the development of modern capabilities, ensuring the nuclear triad remains credible and effective.

Trump’s focus on nuclear superiority aligns with his “America First” doctrine, which emphasizes the importance of military strength in securing peace and stability. By continuing to push for advanced nuclear technologies and modernized infrastructure, a second Trump term could restore America’s position as the world’s foremost nuclear power. A second Trump presidency, therefore, could enhance American nuclear deterrence, ensuring that the arsenal remains a potent force for peace and stability in an increasingly complex global landscape for years to come.

Aaron Holland is a PhD candidate at the University of Utah and is an Analyst at the National Institute for Deterrence Studies. Views expressed in this article are the author’s own.

What Nuclear Deterrence Might Look Like Under a Second Trump Presidency was originally published on Global Security Review.