China’s nuclear strategy and nuclear forces

Regarding nuclear strategy, not only China but also other major countries have used the theoretical frameworks developed in the U.S., such as mutual assured destruction and deterrence, as models. Moreover, these countries have published official documents on nuclear strategy and nuclear forces. However, except for the Defense White Paper published once every few years, China has almost no official documents on its nuclear strategy. In Japan, it is almost impossible to independently investigate China’s nuclear forces, so we have to rely mainly on estimates and analyses by SIPRI (Stockholm International Peace Research Institute), a famous Swedish think tank, and the U.S. military and think tanks for information on the number of nuclear warheads China has and their deployment status.

In fact, Chinese experts on nuclear issues have also developed their discussions by relying heavily on nuclear strategy theories developed in the U.S. Although Chinese strategists have criticized the most basic concepts of nuclear strategy, such as mutual assured destruction, they have never completely rejected them and stopped using them. Even if the Chinese military has not built its forces based on them, there is no doubt that they serve as a reference.

However, it should be pointed out that the U.S. and China each have different views on the nuclear balance.[1] The U.S. approach is predicated on its own military superiority, so it believes that China’s rapid nuclear development is undermining strategic stability and that the U.S. must further enhance its nuclear forces in order to maintain a stable nuclear balance.

On the other hand, China takes the view that it is at a disadvantage, so the enhancement of the U.S.’s nuclear forces and the development of its missile defense networks will weaken the deterrent capacity of China’s nuclear forces against the U.S., making it easier for the U.S. to launch an attack, resulting in a loss of strategic stability and destabilizing the nuclear balance. The balance between the U.S. and China is not a symmetrical one, but an asymmetrical one, so it is only natural that there will be differences in perception of the situation around stability. There is criticism from China as well as the U.S. that under these asymmetrical conditions Robert Jervis’s “stability-instability paradox” (when either the stability of the nuclear balance or the stability of the conventional weapons balance is realized, the other cannot be realized) is less likely to hold.

Even if the views differ, we cannot ignore the fact that they will reach roughly the same conclusion. In order to share the same conclusion, efforts at mutual understanding through close communication are necessary to prevent differences in views from causing misunderstandings and unnecessarily increasing tensions.

Regarding this point, both the U.S. and China, which are trying to avoid nuclear war, have placed particular importance on the idea of strategic stability regarding the nuclear balance and have sought a middle ground. Strategic stability refers to the degree to which the balance is disrupted by external shocks. If this stability is fragile, that is, if tensions rise in the blink of an eye due to a very small shock, it rapidly becomes difficult to control the situation and a crisis will occur. Conversely, if this stability is strong, that is, if tensions do not rise rapidly due to a very small shock, it is relatively easy to control the situation. Therefore, the degree of stability must be increased, vulnerability must be reduced, and stability must be made strong.

Li Bin (Professor at Tsinghua University), known as one of China’s leading nuclear strategy experts, has taken up and discussed nuclear strategic stability. In a world where the abolition of nuclear weapons cannot be easily realized in the foreseeable future and nuclear weapons continue to exist, the overriding imperative is to reduce the possibility of nuclear war occurring. In other words, controlling tensions between nuclear-armed nations and maintaining stability has become the realistic goal.

This concept of strategic stability was originally devised and established in discussions in the U.S. through repeated exchanges with the Soviets during the fierce confrontation between the U.S. and the Soviet Union. It was refined to realize a minimum level of stability between the two countries so that the fierce U.S.-Soviet nuclear arms race during the Cold War era would not lead to a full-scale nuclear war. It is the logic that formed the foundation of the so-called “cold peace,” a peace that could be realized even without mutual trust. This reasoning also applies to the relationship between the U.S. and China in the early part of the 21st century.

As Li Bin says, strategic stability changes depending on the capabilities that can be possessed and the policies that are adopted, so strategic stability takes on a dynamic character. However, this is a major problem, and while the Cold War era thinking continues to be useful, ingenuity is necessary. This is because, as already mentioned, it was technological advances such as MIRV conversion and intermediate-range missiles that have made the evaluation of strategic stability complicated until now.

In U.S.-China relations in the 21st century, China has been working on enhancing its capabilities, while the U.S. has been upgrading its own capabilities and developing new forces, and both sides have been striving to develop an interception network against their opponent’s forces. However, the progress of science and technology is not limited to upgrades to warheads and improvements in delivery vehicles. Game changers, that is, techniques that could make the technology of a generation ago obsolete, have appeared, and the most significant of these is cross-domain.

Cross-domain nuclear strategy

Cross-domain refers to domains which include battles in new fields such as cyber, electromagnetic, space, and the brain, in addition to land, sea and air, which have been the main battlefields up until now. A similar expression is multi-domain. Simply put, multi-domain is just a lineup of various domains but cross-domain emphasizes allies helping each other across different domains, or conversely, influencing each other to destroy or paralyze the military systems of the opponent’s different domains. To put it in a more complicated way, it is a relationship in which interdependence and mutual destruction are realized simultaneously between different domains. The number of weapons that carry out kinetic destruction continues to be important, but the question of how to utilize this cross-domain relationship is greatly involved in exerting numerical superiority. Here we start with space, and subsequently nuclear weapons become involved, but the point is the multi-layered fusion among cross-domains. Cross-domain has already become established as a global trend.

Activities in space, including space weapons, are heavily dependent on communication and information networks (including computers) created by artificial satellite systems. These communication and information networks are vulnerable to cyber and electromagnetic wave pulse attacks. With current technology, these electromagnetic wave pulses are mainly generated by nuclear explosions. As a consequence, the security of space is exposed to cyber threats and threats caused by nuclear electromagnetic wave pulses. Cyber and electromagnetic wave pulse weapons cannot be created without communication and information networks, and given this it can be concluded that they depend on artificial satellite networks in space. Different domains pertaining to communication and information networks, such as space, cyber, and electromagnetic pulses, are intertwined with each other and it is clear that cross-domain fusion and integration are necessary to ensure their unified security. Normally, even if one of the capabilities is much better than the others, if there are weaknesses in other areas, the overall capability will stop at that lowest level.

Moreover, even if nuclear weapons do not directly destroy lives or property, the electromagnetic pulses caused by their explosion will cause enormous damage to the entire world. Since communication networks on Earth are heavily dependent on artificial satellite systems, the intense electromagnetic pulses caused by a nuclear explosion will disable communication in many countries. The damage is incomparably greater than that of a partial cyberattack.

If the communication systems in space are disrupted, the reconnaissance, surveillance, and command and control communication functions of the opponent’s military forces will be greatly impaired not only in space but also in the land, sea, and air domains. In today’s wars, concentrated military forces are attacked immediately if detected, so weapons with differentiated functions are deployed in a dispersed manner to carry out operations. This is the so-called mosaic warfare. This type of operation requires a close communication network and its destruction or paralysis leads directly to defeat.

Moreover, this would cause widespread and massive disruption to not only the military but also to the economy and daily activities around the world, including finance and transportation. AI-related devices, the use of which is exploding, are of course also vulnerable to nuclear electromagnetic wave attacks in the same way. Some people may think that the disruption of only communications would not be very important but that is a big mistake.

It was once hastily concluded that the role of nuclear weapons and nuclear strategy was over with the end of the Cold War, but China continued to place importance on nuclear forces to make up for its lag in the field of high-tech weapons. Moreover, in the early part of the 21st century, the role of nuclear weapons in cross-domain situations is even greater. In Japan, these kinds of discussions were often perceived as nothing more than a pipe dream, but the major countries which have created the concept of command and control in all cross-domains have been advancing the development of this concept. The U.S. military is already building a command and control system based on the concept of JADC2 (Joint All-Domain Command and Control). In addition, the role of AI in JADC2 is already being considered. Chinese experts have also taken into account the U.S. prediction that if AI is used in operational planning, tasks that previously took months could be completed in minutes.

Given this, strategic stability under these new situations and conditions emerges as a problem that must be analyzed. This is one of the major security problems facing modern Japan, and yet it is not well known among private researchers. Therefore, next the author will include an introductory discussion of the cross-domain, which is the foundation of the discussion, and the character of escalation and deterrence there.

Cross-domain “complex deterrence” and escalation

When analyzing the impact of the cross-domain condition on strategic stability, it is necessary to consider whether or not deterrence works effectively in the process of ever greater escalation. Furthermore, if ever greater escalation is considered to be a threat, it will function as a deterrent. Here, to reiterate, cross-domain deterrence is a form of deterrence in which many different domains, such as nuclear, cyber, space, and the brain, cross, that is, they affect each other.

As of 2024, traditional firepower warfare and the quantity of weapons and equipment are being reevaluated in the ongoing Russia-Ukraine war, and there have been excessive expectations for advanced weapons, so the evaluation of advanced weapons and cross-domain has relatively declined. The victories in the Gulf War and the Iraq War were attributed to high-tech weapons and it was thought that the same would be true in the Russia-Ukraine war.

Despite the fact that advanced weapons and cross-domain operations play a major role, they tend to be overshadowed by firepower warfare in media reports. There is no doubt about the importance of firepower warfare, but since it is wartime, it is better to take the view that actually their importance is carefully concealed. There is no reason to stop studying the cross-domain here. The escalation discussed above is also quite closely intertwined with this cross-domain and the nuclear strategy. Here, the author will discuss this aspect.

As the importance of cross-domains has been recognized, the concept has become more complex, as seen in the invention of the term “complex deterrence.” (Note that there is a similar term, “integrated deterrence,” but this is a different concept, referring to the U.S. response to gray zone situations in cooperation with its allies). As a result, complexity has increased and it is no longer easy for prior calculations to keep up. In other words, uncertainty has increased, and if tensions are properly controlled, policies usually become cautious. However, there is a possibility that small moves which were thought in advance to have little impact could bring about major disasters. This is the so-called butterfly effect – the sudden sensitivity and vulnerability of a seemingly stable situation.

In this way, it is expected that international tensions will suddenly begin increasing rapidly, so discussions regarding cross-domain escalation are necessary. Can we assume a certain number of stages similar to the nuclear strategy of the Cold War era, or will cross-domain escalation have an extremely fluid and amorphous character, or will it go back and forth between these two phases? These formulations, such as cross-domain deterrence and escalation, including nuclear deterrence and escalation, are algorithmic warfare in a broad sense, and those who succeed in formulating them first will be able to secure an advantageous stability. This discussion is not easy and the theory is not a perfect prescription or a panacea. However, the opinion that we should stop using existing hospitals and medicines because not all illnesses can be cured is not acceptable and in the same way we will be in deep trouble if we do not have a theory.

It is not possible to comprehensively discuss cross-domain strategy in a limited space. What the author will do here is to create a springboard for considering how China’s future nuclear strategy will develop under the cross-domain condition.