With the Biden administration embarking on its Nuclear Posture Review, it’s time to reexamine the role nuclear weapons play in U.S. national security. While such reviews have become standard when a new team arrives at the White House, President Biden’s comes at a time when key aspects of America’s nuclear forces, such as the Minuteman III intercontinental ballistic missile, are due or past due for replacement or modernization. Although President Trump was a vocal supporter of nuclear modernization programs and even saw a new weapon type deployed and others planned, the current administration and its Democratic allies in Congress are much less enthusiastic.
The expense of overhauling the U.S. triad—the land, sea and air components of nuclear weapon systems—would be considerable, estimated at $1.7 trillion over 30 years. But underlying this issue lurks the question of whether the concepts that brought nuclear weapon systems into being are still operative. Are nations still deterred in their actions by a rival’s ability to unleash existential devastation on them? And if so, how should the U.S. handle its nuclear weapons capability going forward?
Critical Masses: Nuclear Weapons in the Biden Era
Military strategists, foreign policy academics and political leaders formed by the Cold War worldview have lived and worked with the assumption—even assurance—that deterrence is the cornerstone of the international order. Other problems pale in comparison to a nuclear conflagration. Similarly, no national objective would be worth attaining at the cost of the nation’s destruction.
While nine nations are known to have some nuclear weapons capability (Israel has not declared its status, and North Korea’s ability to actually field such weapons is unclear), there has not been a major war between these countries. There have been clashes—such as between India and Pakistan—that produce anxiety, but calmer heads hitherto have prevailed. Nuclear-armed nations have warred with nonnuclear ones in the post-World War II era without the former resorting to the use of atomic weapons, even when the war has gone badly. Such restraint is almost certainly due in part to the international pariah status awaiting a first user of nuclear weapons in the modern era.
A new wave of arms-control advocates is lobbying the Biden administration to use the opportunity of the Nuclear Posture Review, which establishes U.S. nuclear policy, strategy and capabilities for the next five to ten years, to declare a “sole purpose” policy for U.S. nuclear forces. In a nutshell, this is an extreme version of a “no first use” policy, where in addition to pledging not to use nuclear weapons first in any conflict, we would be stating that the only reason our nuclear arsenal exists is to deter nuclear attack and, if necessary, to retaliate if so struck. China has declared a no-first-use policy. Russia abandoned this stance in 1994 and now reserves the option to strike first.
The United States currently has a more nuanced position: It pledges not to use nuclear weapons under any circumstances against nonnuclear countries that are party to the Nuclear Nonproliferation Treaty, while reserving the option to use nuclear weapons against others under certain circumstances. The ambiguity of this “will we or won’t we?” policy is designed to deter rogue states and nuclear-armed rivals (i.e., Russia and China).
In 2017, Vice President Biden stated that he thought the United States could safely adopt sole purpose at that time. There is no reason to believe Biden has changed his mind on the issue as president. The adoption of such a policy would be very tempting. Foremost, it would enable the administration to cancel or at least pause a number of nuclear modernization programs that are on many Democrats’ hatchet lists, such as a replacement for the Minuteman III and nuclear-armed cruise missiles. Over time, sole purpose would enable the United States to eliminate all but the few hundred weapons—probably submarine-based—needed to retaliate against a nuclear attack, presumably by destroying the offender’s cities. What other prospective retaliation would constitute deterrence with so few weapons on hand?
And there’s the rub. Would a U.S. president be prepared to order a retaliatory strike on an enemy city in response to a nuclear strike on an aircraft carrier task force? Or against the territory of an ally? The domestic and international pressure to forgo such vengeance would be extreme—so much so that an enemy might risk a nuclear strike for tactical advantage against the United States or an ally, assured that no retaliation would be forthcoming.
A January paper by the Carnegie Endowment for International Peace says that U.S. allies might perceive such arm-tying declarations as signaling a lack of American resolve to come to their aid in a crisis. It might also signal the same to potential aggressors. The paper’s authors suggest the United States should instead declare an “existential threat policy,” where it would use nuclear weapons “only when no viable alternative exists to stop an existential attack against the United States, its allies, or partners.”
Although this formulation is arguably ambiguous, the paper recommends specifying the circumstances in which the use of nuclear weapons would be justified. It also says a range of nuclear weapons types is required to enable a proportional response to a nuclear threat beyond targeting enemy population centers, which is no longer a credible threat from an American president. In short, deterrence will not be possible unless the U.S. retains weapons to cover many contingencies.
Bombs and Rockets: Nuclear Strategy 101
Strategic considerations over when and how to use nuclear weapons have evolved since the Cold War, which itself developed in the wake of the totality of conflict in World War II. U.S. generals could contemplate using the atomic bomb during the Korean War, when America essentially had a monopoly on deliverable weapons, but for many sound reasons this did not happen.
Nevertheless, as technology advanced and East-West blocs solidified, nuclear weapons proliferated in form and function. At the one end of the scale were city-busting hydrogen bombs, and at the other were “tactical” warheads of much less destructive power envisioned for routine warfighting. Strategists intended to use tactical nuclear weapons in battlefield situations against land, sea and air targets. Think of them as vastly more powerful versions of conventional weapons. There were nuclear-tipped missiles for shooting down bombers, depth-charging submarines, blasting tank formations and striking important sites such as radars, airfields and command centers.
A lot of this is past tense because of the omnipresent danger that any use of nuclear weapons could draw retaliation that could escalate into an exchange of strategic nuclear weapons. “The Bedford Incident,” a 1965 film with Cuban Missile Crisis overtones wherein an American destroyer and a Soviet submarine ultimately destroy each other with tactical nukes, showed that the dangers of this situation were already percolating in the popular imagination. Any military conflict between nuclear-armed nations is automatically at risk of going nuclear, and whatever battlefield advantage might be gained from tactical nukes would be nullified once cities start going up in smoke. The United States and Russia largely have withdrawn tactical nuclear weapons from deployment, although both retain the capability to deliver smaller nuclear strikes via aircraft and missiles.
Strategic nuclear forces are much more front and center in the public imagination and thus in the briefs of elected lawmakers who cut the checks for them. Anyone growing up during the Cold War will recall periods when a large-scale exchange of nuclear weapons between NATO and the Warsaw Pact seemed possible, even likely. The sheer number of weapons deployed and the short timelines between launch and strike, particularly in Europe, meant every increase in East-West tensions carried fresh fears of nuclear war.
Both the United States and the Soviet Union extensively studied various cold-blooded strategies for using nuclear weapons preemptively against each other. Many plans involved so-called counterforce strategies, where one side would try to destroy the other’s arsenal before it could be used against them. Technology and political realities ultimately made such first-strike gambits so extremely risky and unlikely to succeed that they were impossible to achieve, even with the appropriate levels of cold-bloodedness.
Even if the U.S. or the USSR tried to restrict its nuclear strikes to military targets, some of these would be located near cities (e.g., the naval submarine base near Groton, Connecticut). Once the attacker hits an enemy city, the attacker’s own cities are going on the plotting board. This is where nuclear deterrence dwells: Presumably the Russians love their children, too.
Deterrence still holds sway among many policymakers, in and out of uniform. They perceive that it has kept the peace for 70 years, at least among the nuclear powers. It may have prevented India and Pakistan from going at it hammer and tongs recently. It may be keeping Israel on the map. It may keep China more thoughtful in its rise to great power status. Conversely, China’s growing nuclear deterrent may force the United States to address China more deftly than it might otherwise choose to.
Or none of this may be true in practice. The interesting aspect of nuclear deterrence in the post-Cold War era is that it seems like received wisdom. Absent some transformational event in the human heart, the prospect of retaliation remains a reasonable explanation for behavior. However, the era where a large-scale nuclear exchange between rival superpowers seemed a plausible fear has receded to the back of people’s minds, if not dropped out altogether. It is possible that humanity has evolved to where the “unthinkable” really has become so.
U.S. and Russian warhead stockpiles have shrunk dramatically since the crescendo of the Cold War, when every other 1980s pop song seemed to be about the impending nuclear holocaust. Under the provisions of the New Strategic Arms Reduction Treaty, signed by the United States and Russia in 2010, both sides agreed to limit the numbers of deployed warheads to 1,550 apiece. The deal is active until February 2026 and could be extended further.
Many advocates of no-first-use and sole-purpose policies say the time has come to eliminate nuclear weapons as warfighting tools. Regardless of how Russia or China (or Iran) feels about the matter, that goal may be in sight from the U.S. side, which merely has to do nothing to see its nuclear arsenal slide into obsolescence.
Brad Roberts, director of the Center for Global Security Research at Lawrence Livermore National Laboratory, recently told interviewer Lindsay Morgan of the Institute on Global Conflict and Cooperation at the University of California, San Diego that the United States was rapidly approaching a point where it would have to modernize its nuclear arsenal or effectively disarm unilaterally:
During the Cold War, we had the ability to produce thousands of weapons the way the Soviets did. But the main production plant was closed in the 1990s. The U.S. nuclear enterprise, as it is called, is constrained by heavy oversight and a set of rules that oblige the complex to refurbish warheads with exactly the same materials, technologies, and techniques that were used to produce them in the 1960s, ’70s, and ’80s. Some of those materials don’t exist anymore. Refurbishing warheads could be done more cheaply and much more quickly if there were some relief from those constraints. But what elected official is going to say, “Let’s loosen the constraints on America’s nuclear weapons complex?”
President Trump, arguably, was one such official. He okayed U.S. Navy plans to deploy the more accurate, lower-yield W76-2 warhead modified from an existing design aboard ballistic missile submarines. Critics of this decision object on two counts: First, it is a “new” nuclear weapon (even though Russia and China continue to introduce new and modernized nuclear weapon types). Second, such less destructive but more accurate weapons could be used in counterforce strikes that, as outlined above, are most effective as preemptive (first-strike) attacks. Rep. Adam Smith (D-Wash.), chairman of the House Armed Services Committee, strenuously opposes deployment of the weapon.
The tension over weapons like the W76-2 warhead and policies like sole purpose will be part of the Biden administration’s Nuclear Posture Review. In an era where even discussion of nuclear weapons and policy seems archaic to most Americans, it is easy to envision how the White House and Congress would shun the previous president’s enthusiasm for nuclear forces and embrace the doves. Less clear is how far supporters of a multifaceted and modern nuclear deterrent for America are willing to press the issue.
Were the United States to adopt a sole-purpose policy and pare its nuclear arsenal back accordingly, then deterrence truly would be dead. Limiting threats to retaliation against cities is no deterrent at all; nobody will believe it. Likewise, effective unilateral disarmament by refusing to modernize America’s arsenal generates no confidence from its allies and gives its rivals a freer hand.
Russia has proven itself adept at using force and managing escalation right to the point where a Western military response seems possible. This has happened in Georgia, the Crimea, eastern Ukraine, and to some extent Syria. Russia counts on its existing arsenal of nuclear weapons and a slowly modernizing cadre of new ones, such as its hypersonic missile systems, to deter the West from objecting too strenuously to adventures in what it considers its sphere. The seeming willingness of Russia to use force, even suggestions of nuclear force, to achieve its objectives acts as a deterrent to Western intervention because the threats are believable.
China, while more deliberative in its development and deployment of nuclear weapons, clearly believes in the value of modern forces to deter aggression and perhaps overawe regional rivals. Moreover, its nuclear deterrent bolsters its area-denial strategy using conventional forces to keep the U.S. military out of the Western Pacific in the event of armed conflict.
For the United States to maintain a credible nuclear deterrent, it has to be willing to field an effective—and usable—nuclear arsenal of sufficient variety and numbers to back up its threats in a proportional way.