Growing tension on the Korean Peninsula has returned the unimaginable terror of nuclear war to the American public consciousness. The danger is a global one: Nine states possess nearly 15,000 nuclear weapons and the detonation of even one of these weapons could cause humanitarian and economic catastrophe. Although the use of a nuclear weapon by a state or non-state actor is unlikely, it is not impossible, and the risk may be growing. Indeed, such a rare event can be evaluated in terms of a simple risk-assessment formula: probability multiplied by consequences.
Given the enormous consequences of nuclear use, even small fluctuations in probability warrant attention. Some variation will arise from changes in the international environment, such as technological advances that make nuclear command and control systems more or less vulnerable to cyber-attack, or fluctuation in the level of tension between nuclear-armed rivals like India and Pakistan. But as the world’s most powerful state, with its own vast nuclear arsenal as well as a record of leadership in nonproliferation and nuclear security efforts, the United States plays an important role in moderating —– or enhancing —– the likelihood of nuclear use.
President Donald Trump’s comments during the campaign and transition prompted widespread concern about his cavalier attitude toward, and lack of knowledge about, the world’s deadliest weapons. Since taking office, he has tempered his rhetoric somewhat —– but more than 100 days into the Trump administration, there are early warning signs indicating the president’s policies could increase the risk of nuclear catastrophe.
Setting aside accidental launch or detonation, the most likely scenarios for the intentional or miscalculated use of a nuclear weapon are nuclear detonation by a state during crisis or wartime, and nuclear use by a non-state actor, such as a terrorist group. While this president is nothing if not unpredictable, it is both important and possible to sketch out how such a nuclear use might play out. The five risks described below are meant as a starting point for that discussion.
Risk #1: Nuclear First-Use by the United States
First, the president has the sole authority to launch nuclear weapons through the “nuclear triad” of land, sea, and air-launched systems. The horrific consequences, fear of retaliation, and extraordinary capabilities of U.S. conventional forces militate against nuclear use in all but the most extreme circumstances. Nonetheless, Trump’s impulsive temperament, obsession with projecting strength, and aversion to normative constraints may make him more prone to nuclear use than other recent presidents. Beyond these already-perceptible presidential proclivities, the Nuclear Posture Review —– which recently began under Pentagon leadership —– will elucidate the administration’s declaratory nuclear doctrine, providing the first concrete indication of scenarios in which the Trump administration would consider nuclear use.
Risk #2: Inadvertent Nuclear Escalation
Second, the Trump administration’s penchant for sending mixed signals increases the risk of misperception in the event of a crisis or war involving another nuclear state. Trump is famously mercurial, abruptly changing positions on issues ranging from NATO’s obsolescence to the desirability of nuclear proliferation. Rather than allowing the White House communications staff to clarify his positions, Trump often contradicts them. In December, for example, when aides sought to soften Trump’s call for the United States to “strengthen and expand” its nuclear arsenal, Trump went on the record a second time to threaten an arms race. Moreover, senior national security aides frequently stake out divergent policy positions – with the president’s apparent encouragement — as exhibited by the slew of incompatible explanations for Trump’s April decision to launch cruise missiles into Syria. The result is confusion surrounding whose statements represent administration policy —– a whiplash effect most recently on display in the back-and-forth on North Korea. Though the president seems to believe unpredictability creates bargaining leverage, it also prevents the administration from credibly telegraphing its intentions. This dynamic makes diplomacy difficult and privileges potentially escalatory military displays to demonstrate seriousness. If a crisis were to reach boiling point, the Trump administration would struggle to turn down the heat by credibly signaling restraint or limited aims. Moreover, amidst rising tensions, a weaker adversary would have little choice but to engage in worst-case-scenario planning, and a threatening tweet impulsively dispatched by the president could provoke a foreign leader to gamble on a first strike rather than risk U.S. preemption. Beyond contingencies that directly implicate the United States, Trump’s slippery reputation could also hinder his ability to arbitrate international disputes involving nuclear powers —– for example, if war were to break out between India and Pakistan.
Risk #3: A Lower Global Nuclear Threshold
Third, Trump has tempered his most incendiary campaign rhetoric on the subject of nuclear weapons —– but serious consequences would accompany a return to positions that promote nuclear proliferation and lower the normative threshold for nuclear use. Encouraging U.S. allies and partners like South Korea, Japan, and Saudi Arabia to go nuclear —– whether explicitly or by stoking fears of abandonment —– could spark atomic arms races in already-unstable regions. In addition, the administration’s recent extension of sanction waivers suggests its intent to abide by the terms of the Iran nuclear deal —– but a presidential decision to abrogate the “worst deal ever,” whether through outright withdrawal or accumulated acts of subtle sabotage, would likely spark an acute crisis. Proliferation risks would be further compounded by threats to use nuclear weapons first in unnecessary contingencies, such as against the self-proclaimed Islamic State, eroding the non-use norm that has contributed to nuclear restraint since 1945.
How might the Trump administration’s policies affect the likelihood of nuclear use by non-state actors? Terrorist groups are liable to use whatever lethal material they can get their hands on —– as demonstrated by the Islamic State’s employment of rudimentary chemical weapons in Iraq and Syria —– so the critical limiting factors are access to nuclear weapons, material, and expertise, and the ability to move it across international borders. Two additional factors will impact the U.S. government’s ability, in concert with international partners, to thwart such threats.
Risk #4: Diminished Domestic Capacity to Prevent Nuclear Terrorism
The United States’ capacity to counter nuclear terrorism will depend on the Trump administration’s resource decisions. Within the U.S. government, responsibility for the prevention of WMD terrorism is spread across numerous agencies with interlocking functions: From Department of Energy labs developing nuclear detection technology, to the Department of Homeland Security conducting radiological monitoring at U.S. ports, to intelligence and law enforcement agencies tracking threats, to the State Department coordinating with other countries to limit the spread of nuclear weapons globally, to Department of Defense training special operations forces to render safe nuclear weapons or material. Sustaining such capacity requires personnel and funding. The administration’s slow pace of political appointments creates risk by hobbling agency leadership, hindering inter-agency collaboration at the senior level, and creating a vacuum when it comes to defining affirmative policy priorities. The extent to which the Trump administration seeks funding for nuclear security-related programs in their proposed fiscal year 2018 budget —– expected to be released on May 23 —– will indicate the level of priority the administration assigns to mitigating WMD terrorism risk. (The Trump administration’s budget blueprint does not specifically address this issue.)
Risk #5: Weakened International Nuclear Security Cooperation
Finally, a withdrawal from international nonproliferation and nuclear material security cooperation could increase the risk of nuclear use by a non-state actor. If the Trump administration follows through on its avowed skepticism of multilateral institutions —– most notably the U.N. system —– critical cooperative mechanisms could be placed in jeopardy. The International Atomic Energy Agency (IAEA), for example, is a U.N. agency that advances best practices in safeguarding nuclear material around the world. It maintains a global database for tracking lost or stolen nuclear materials, among other vital functions. The IAEA relies on U.S. contributions for roughly a quarter of its budget and withholding those funds would severely hinder its effectiveness. Similarly, an administration disdainful of U.N. bodies is unlikely to break the diplomatic logjam over restrictions on the production of nuclear material through the Fissile Material Cutoff Treaty, and may not insist upon stringent IAEA safeguards as a precondition for future agreements on civil nuclear cooperation. Beyond formal institutions, the Obama administration initiated a Nuclear Security Summit process, which convened global leaders to take concrete steps toward reducing the risk of nuclear terrorism. Whether the Trump administration maintains this focus and pushes for implementation of commitments made at past summits will further impact risk going forward.
Nuclear detonation, whether by a state or non-state actor, remains an extremely remote possibility, and the risk of such a rare event is difficult to quantify. Nonetheless, the catastrophic consequences of nuclear use demand attention —– not only from the White House, but also from Congress and the American people. Fortunately, the Trump administration is still in its early days and has ample opportunity for progress. “I hate nuclear more than any,” the president said during the 2016 campaign when asked about nuclear weapons. Action to address the five risks described above —– as part of a comprehensive nonproliferation and nuclear security agenda —– will signal the seriousness of the administration’s effort to reduce nuclear dangers.
Dr. Rebecca Friedman Lissner is a Stanton Nuclear Security Fellow at the Council on Foreign Relations. Previously, she served as a Special Advisor to the Deputy Secretary of Energy.
U.S. Air Force photo by Senior Airman Ian Dudley