Nuclear Dilemma: The United States grapples with a growing global threat

For the first time in its history, the United States is being faced with the problem of nuclear deterrence not of a single country (Russia) but of several. This challenge demands fundamentally new approaches and methods from Washington. Although the world's nuclear arsenal as a whole is shrinking, as previously reported, this is mainly due to the dismantling of decommissioned warheads in the United States and Russia, which collectively represent 90% of the total count. The pace of this reduction has slowed down, according to the Stockholm International Peace Research Institute (SIPRI), there were 198 fewer warheads in the world in 2022, and 391 fewer in 2021. China, on the contrary, has been seeking to increase its nuclear arsenal in recent years. According to SIPRI, China's warhead count remained unchanged in 2021 but increased by 60 in 2022. North Korea, for which nuclear weapons are a central element of its military strategy, added five warheads to its arsenal in 2022, and closer ties between Pyongyang and Moscow could potentially provide them with more advanced delivery systems. India and Pakistan are also increasing their stockpiles, with SIPRI reporting that their arsenals grew by four (to 164) and five (to 170) warheads in 2022, respectively. As of the beginning of 2023, nine states – the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea, and Israel – possessed a total of 12,500 warheads, with 9,500 of these in operational readiness. This is 86 more warheads than the year before. About 2,000 warheads, mostly Russian and American, were placed on high alert, meaning they could be used instantly.

As noted in the report 'Qualities Precede Quantities: Deciding how much is enough for US nuclear forces' by Edward Geist, an expert at RAND, historically, Washington has historically sought numerical parity in the balance of strategic nuclear forces with Moscow, believing that other possible adversaries (e.g., China) have much smaller nuclear arsenals to consider their deterrence as a separate task. Today, however, the effectiveness of this approach has come into question, not only because of Beijing's continued attempts to build up its nuclear arsenal, but also because of new threats from Pyongyang and Moscow. 

Although the size of North Korea's nuclear arsenal remains relatively modest, the country has made far more progress in the face of tough sanctions than experts anticipated in developing warheads and delivery systems. Russia, for its part, continues to work on new nuclear weapon delivery systems, including long-range torpedoes and cruise missiles. Against the backdrop of increasingly alarming rhetoric by Russian politicians and public figures regarding the potential use of nuclear weapons in Ukraine, the Russian nuclear potential is now considered a much more serious threat than previously thought.

In this situation, a successful nuclear deterrence strategy for the United States would involve making potential adversaries understand that Washington possesses sufficient nuclear capabilities to confront other nations, and American policymakers are prepared to use them if necessary. As Geist writes, the effectiveness of deterrence is determined not just by raw numbers but also by the perception of the threat and the willingness to use nuclear weapons.

One of the most challenging aspects, according to Geist, is the issue of tactical deterrence against the use of relatively small nuclear weapons by an adversary. Geist identifies four possible approaches to tactical deterrence.

1. Threat of Full-Scale Nuclear War: This approach involves using the threat of a full-scale nuclear war to deter an adversary from using tactical nuclear weapons. The idea is to convince the opponent that escalation would spiral out of control, turning a tactical nuclear conflict into a strategic one that would ultimately lead to mutual destruction. However, the effectiveness of this approach is questionable, as the adversary may decide that a response to a local nuclear attack that would bring death to the entire civilisation is still unlikely.

2. Proportional Response: A proportional response to the use of tactical nuclear weapons is the second approach proposed. Yet, determining what constitutes a proportional response is challenging. It is unclear whether similar weapons should be employed or equivalent targets should be selected. In any case, the adversary may still perceive such a response as an act of escalation.

3. Escalation Game: The third approach involves a game of increasing stakes to persuade the adversary of one's unwavering commitment to escalation if necessary. In a simulation of nuclear deterrence, players with a greater willingness to escalate emerged victorious over more cautious opponents. However, the success of this strategy hinges on the ability to undermine the adversary's resolve. Otherwise, playing this escalation game could lead to catastrophe.

4. Non-Nuclear Response: The final approach entails forgoing a nuclear response and inflicting unacceptable damage on the adversary by conventional means. However, this strategy may be questioned by both adversaries and American allies, as they may be unsure how to interpret the absence of a nuclear response to a nuclear strike.

An important limitation for the United States is the fact that it does not appear to have tactical nuclear weapons equivalent to those developed by Russia. The development of an American sea-launched cruise missile had been previously suspended, a decision that some experts at the Atlantic Council consider an error.

Nonetheless, the analysts at RAND believe that possessing such missiles could in some situations weaken nuclear deterrence. First, it might convince the adversary that such weapons would be the primary means of retaliation. This could increase the likelihood of the adversary launching a tactical nuclear strike first in order to neutralise US capability. Second, US sea-launched cruise missiles are visually almost indistinguishable from conventional missiles such as the Tomahawk. This poses a dilemma for the US military leadership: could they use Tomahawks for conventional strikes, knowing that the adversary might mistakenly interpret this as the beginning of a nuclear conflict and respond accordingly?

The complexity of the deterrence problem is further compounded by the increasing number of nuclear-armed states and the intricate web of relationships between them. For example, China, which has approximately 400 nuclear warheads, is embroiled in territorial disputes with India, which is also modernising its nuclear arsenal. The course of their confrontation could affect the pace of development of Beijing's military nuclear program.

In a speech in June of this year, the US National Security Advisor, Jake Sullivan, stated that the US response to growing nuclear threats would not involve increasing the size of its nuclear forces. To develop an effective strategy, the RAND analysts propose using the concept of a 'double mirror,' that is, to assess how the opponent sees the US nuclear potential and how they take this into account in the development of their own strategy.

For example, Moscow has always planned the size of its nuclear forces in such a way that they would be capable of inflicting 'unacceptable damage' on the US if necessary — this criterion would be met by a nuclear strike with warheads totalling 50-150 megatons. However, the developers of Russian nuclear strategy believe that Washington only needs a few dozen warheads to deliver an effective retaliatory strike against Russia, according to the RAND study. This means that to deter Russia, it is sufficient to have deployed cruise missiles on several submarines. Using the 'double mirror' concept to deter China and North Korea according to the same logic appears to be an even simpler task.

According to RAND, regardless of the chosen number of nuclear warheads, the US needs to improve the quality of its strategic capability management. This requires Washington to improve its management of its strategic nuclear forces, which must be able to rapidly assess emerging threats and find an adequate response to them. This is particularly true at a time when the threat of nuclear weapons is more real than during the Cold War arms race.