The nuclear elephant in the room: To restrain or disarm?

US President Joe Biden has made clear through his national security appointments that he intends to maintain many of the same foreign policy priorities as the last Democratic president, Barack Obama. In December, US national security adviser Jake Sullivan said in a live-streamed conference that Biden wants to get Iran “back into compliance” with the Iran nuclear deal, an Obama-era agreement meant to prevent Iran from getting a nuclear bomb. President Donald Trump withdrew from the deal in 2018, and Iran has since breached it by incrementally enriching uranium beyond the deal’s limits. Nuclear nonproliferation will clearly be a priority in the Biden administration.

Equally important for nuclear nonproliferation, but less noticed by the US media, were remarks made in November by Kim Chong-in, the interim leader of the opposition People Power Party in South Korea. Kim said Seoul’s “conventional position on nuclear weapons”—i.e., not having them—“should be revisited” if US efforts to denuclearize North Korea continue to fail. This statement came only three years after South Korea’s mainstream conservative political party demanded the return of US nuclear weapons to South Korea for the first time—a sign of South Koreans’ eroding trust in Washington’s existing nuclear weapons posture, which places no nuclear weapons in South Korea. Polls consistently reveal majority support in South Korea for obtaining nuclear weapons, either under US or South Korean control.

America’s nuclear nonproliferation challenges in the Biden era and beyond will come not only from adversaries like Iran and North Korea, but also allies and partners, including South Korea and Saudi Arabia. Support in the United States for foreign policy restraint further complicates these challenges. If Americans are to seriously consider nuclear disarmament in a future molded increasingly by restraint, they will first need to acknowledge the fundamental tension between restraint and disarmament.

A rise in restraint. Recent years have seen a remarkable shift toward a more diverse foreign policy landscape in Washington. In his 2018 book The Hell of Good Intentions, Harvard University international relations professor Stephen M. Walt identified only one “inside-the-Beltway think tank,” the Cato Institute, that consistently criticizes US attempts to create a liberal world order. A little over a year ago, though, the Quincy Institute—which envisions “a world where peace is the norm and war the exception”—opened its doors, calling for greater restraint in US foreign policy. And in 2019, in an attempt to end US support for the Saudi-led military intervention in Yemen, Congress for the first time passed a resolution invoking the War Powers Act, a law intended to check executive overreach after the Vietnam War (though President Trump later vetoed it).

The growing appeal of foreign policy restraint—a grand strategy that calls on the United States to scale down its global military sprawl—is also evident in the prominence of American politicians across the political spectrum who have challenged select aspects of liberal hegemony, from Senator Bernie Sanders to President Donald Trump. Moreover, the coronavirus pandemic has shown Americans that some of the greatest threats to US national security cannot be combated by an expansive military policy. Decades after restraint was first enunciated in academic circles, the future appears to be growing brighter for “restrainers,” who remain skeptical of committing US troops abroad in most or all cases.

What the shift toward military restraint bodes for nuclear disarmament efforts, however, is currently underdiscussed. On the issue of nuclear weapons, this lack of sufficient discussion could lead Americans to overlook crucial differences between restrainers and advocates of nuclear disarmament. This is easy to do, as both communities strive for a more peaceful US foreign policy. But a closer look at the policies advocated by restrainers and those who favor nuclear disarmament reveals a fundamental tension between the two.

Similarities and differences. Restrainers and disarmament advocates both desire a more peaceful US foreign policy. But, with regard to the bomb, there is remarkably little shared ground. First, the similarities: During the Cold War, Washington built up a massive nuclear arsenal because doing so was supposedly necessary to deter an attack by the Soviet Union on the homeland or US allies. Many restrainers would argue that the size and setup of the arsenal was unnecessary and dangerous, because a state only needs a secure second-strike capability—and nothing more—to successfully deter adversaries. Disarmament advocates also hope for a trimmer US nuclear arsenal. In their eyes, to play on the words of a famous scholar, more is never better.

Disarmament advocates, though, aim for a world completely free of nuclear weapons. Citing the horror of the Hiroshima and Nagasaki bombings (not to mention the high toll of nuclear testing since then) and several close calls with nuclear catastrophe since 1945, they have long argued that nuclear weapons must eventually be eliminated if humanity is to survive. According to the International Campaign to Abolish Nuclear Weapons—an umbrella group of civil society organizations committed to nuclear disarmament—nuclear weapons do not keep the peace, but instead “pose a direct and constant threat to people everywhere.”

Here, restrainers disagree. Far from viewing nuclear weapons as an unqualified threat to humankind, they will admit that their favored policies may well lead to more countries pursuing and acquiring nuclear weapons. Because restrainers believe that Washington should stop providing certain allies and partners with massive troop garrisons and coverage by the US nuclear arsenal—a policy known as “extended deterrence”—they are often content to leave countries like Japan and South Korea to take on the brunt of their own defense burdens. For a country like South Korea, which has latent nuclear weapons capabilities and faces a nuclear-armed adversary open to forceful reunification, this would likely lead to the pursuit of an indigenous bomb. Whatever their concerns about the US nuclear arsenal, many restrainers are comfortable with some added proliferation risk, whereas disarmament advocates are not. For example, Walt, a restrainer, said five years ago, “Iran’s acquisition of a nuclear weapon would not be that significant an event.”

How do restrainers justify their stance? Many will concede that the danger posed by nuclear proliferation is real (though some argue that some purported risks of proliferation are overblown). Some also argue that a restrained US foreign policy is not necessarily that much more conducive to nuclear proliferation than the status quo, as the latter has had a mixed track record on halting nuclear proliferation. (India, Pakistan, and North Korea all joined the nuclear club after the United States adopted its present policy of nuclear nonproliferation.) After all, if history is any guide, a more militaristic US foreign policy entails ambitious projects of regime change—a prospect that drives rational foreign leaders to pursue deterrent weapons, such as nuclear bombs. Libya’s Muammar Gaddafi gave up his pursuit of nuclear weapons, only to pay with his life. This lesson has not gone unheeded by the Kim family in North Korea.

However, restrainers’ optimistic view of nuclear proliferation is most open to the critique that a departure from the decades-long US mission to limit the spread of nuclear weapons could present humanity with uncertainty of unprecedented magnitude. It is this uncertainty that disarmament advocates deem unacceptable.

But disarmament advocates are not without their own theoretical shortcomings. Many advocates of nuclear disarmament maintain the bold position that Americans can restrain US foreign policy to make it more peaceful while also avoiding the nuclear proliferation allowed by restraint. While disarmers are certainly reasonable to reject the regime-change policies that help drive nuclear proliferation, here they neglect that, at least in the short term, US nuclear weapons are partly responsible for the absence of Japanese and South Korean ones. Furthermore, their dual pursuit of peace and disarmament relies on a belief in something beyond a globally dominant US military—international law, perhaps—that can sufficiently staunch nuclear proliferation (not to mention push existing nuclear weapons states to disarm).

To be sure, international law seems to have limited the spread and contributed to the non-use of nuclear weapons. Moreover, restraint and nuclear threat reduction are compatible in certain ways. Experts such as MIT political scientist Barry R. Posen emphasize that a restrained foreign policy would still allow Washington to be active in managing nuclear proliferation in as safe a manner as possible. But international law was not enough to prevent the latest member of the nuclear club, North Korea, from acquiring its own deterrent. And, in any case, a growing nuclear club will not sit well with advocates of fewer nuclear weapons. Those who place a high premium on nuclear disarmament should fear a US foreign policy of restraint.

Peace and nonproliferation: uneasy partners. These differences have real implications for current US nonproliferation policy. Restrainers who want to remove from Washington’s toolkit once and for all the frightening option of preventive strikes on Iran or North Korea may welcome the proliferation of nuclear weapons to Iran and would almost certainly put less focus on de-nuclearizing Pyongyang. Such developments would not sit well with disarmament advocates.

This disagreement is certainly not new. Most prominently, political scientists Kenneth N. Waltz and Scott D. Sagan long debated whether proliferation leads to peace or ought to be opposed, respectively. Their discussions continue to influence debates today, and the questions they ask have only grown more pressing as restraint appeals to more and more Americans.

Of course, peace and nonproliferation are compatible in certain circumstances. Disarmament advocates should not be chastised for pursuing both in places like Iran. The Joint Comprehensive Plan of Action made clear that leaning on diplomacy, not just military might, is the best hope for avoiding a nuclear-armed Iran.

But wedding the dual goals of peace and nonproliferation becomes much more tenuous where the latter can largely be attributed to US military hegemony and the decidedly unrestrained grand strategy of sprawling alliance commitments. Only a little over a year ago, Turkish President Recep Tayyip Erdogan deemed it unacceptable that Turkey was not allowed to have nuclear weapons under international law. If not for Turkey’s NATO status and protection by the US nuclear arsenal, one can imagine Erdogan rectifying that “unacceptable” prohibition by building his own nuclear weapons.

Moreover, while their contribution to nonproliferation is clear, alliance commitments like NATO can hardly be described as entirely peaceful today: Precisely because it is powerful enough to prevent proliferation, NATO has initiated regime change (followed by civil war and state collapse) in places as distant as Afghanistan and Libya. And it is doubtful that the world’s great powers would have been graced by “the long peace” without a nuclear check on aggression. Peace and nuclear nonproliferation are hardly easy partners.

The expansive foreign policy long practiced by Washington has contributed substantially to nuclear nonproliferation, a prerequisite of total nuclear disarmament. But insofar as a shift toward restraint entails deep cuts in defense spending and drawdowns from legacy commitments of US forces abroad, restrainers imperil the ambitious goal of disarmament. If Americans grow more willing to take a chance on a new grand strategy, uncertainty about the contours of a restraint-based US foreign policy will become a less convincing argument for staying the current course, and nonproliferation will likely become a lower priority in Washington. Disarmament advocates will be increasingly pressured to choose between the incompatible goals of peace and nuclear weapons abolition. The implications of their choice could hardly be greater.

Editor’s Note: The views expressed here are the author’s own, and do not reflect those of the Wisconsin Project on Nuclear Arms Control.