Executive Summary

This report examines the evolving deterrence dynamics between the United States and the People’s Republic of China (PRC) in the space domain. During the Cold War, nuclear deterrence helped maintain the peace between the United States and the Soviet Union, and it remains a cornerstone of US defense policy today. However, for reasons both geopolitical and technological, the ability of any country to deter another from attacking its space assets is being called into question.

China’s People’s Liberation Army (PLA) is acquiring and developing a range of counterspace capabilities and related technologies, including kinetic-kill missiles, ground-based lasers, and co-orbital satellites, as well as the space surveillance capabilities that enable their use. The use of these weapons against the US space architecture could threaten US military superiority by undermining the command, control, communications, computers, intelligence, surveillance, and reconnaissance capabilities that enable the US military to operate in the Indo-Pacific and project power globally.

APPLYING DETERRENCE TO THE SPACE DOMAIN

We define space deterrence as one country dissuading another country from interfering with systems that operate in space or support the operation of space systems from the ground. Numerous variables can complicate the success of deterrence in the space domain. Deterrence dynamics may be influenced by whether attacks are reversible or irreversible, terrestrial or space-based, kinetic or non-kinetic, and lethal or non-lethal.

The effectiveness of space deterrence could be shaped by the type of weapon. Nuclear weapons, kinetic weapons, and non-kinetic weapons, such as electronic countermeasures, directed energy weapons, and cyber weapons, could all be used against space assets. Space deterrence could also include preventing attacks against launch sites and other facilities using conventional munitions, such as bombs and missiles.

Reversibility of attacks: different types of weapons produce different types of effects. Reversible attacks, such as jamming GPS and communication signals or temporarily blinding optical sensors with a laser, may be more difficult to deter because of their low cost and reduced escalatory potential. The effects of other non-kinetic weapons, such as high-power microwave weapons, may not be reversible, so these weapons may be viewed as having a higher cost. Debris-producing kinetic attacks may be viewed as both costly and escalatory because of the long-term effects that debris can have on space systems in general.

The type of space asset targeted may also influence whether an attack can be deterred. Attacks against scientific satellites with little or no military value may generate less of a reaction, although their civilian or scientific value may discourage attacks. On the other hand, attacks against satellites that are few in number but in high demand may generate a stronger reaction. Attacks against large satellite constellations may be viewed as less escalatory because the loss of any one satellite may not appreciably degrade the constellation’s overall capability. However, an attack on large portions of a satellite constellation may be viewed as escalatory.

Space-based versus terrestrial targets: kinetic attacks against space-based assets may be viewed differently from those against terrestrial targets. Kinetic attacks against ground facilities, such as a launch site, may be more escalatory than kinetic attacks in space because the targets are located on sovereign territory. Attacks resulting in the loss of life would likely be viewed as the most escalatory, thereby receiving the strongest reaction.

DETERRENCE FACTORS AS APPLIED TO SPACE AND US-PRC RELATIONS

We derived 10 factors that could affect the US’s ability to deter China in the space domain. We organize these factors based on military balance of power unique to the space domain, challenger (PRC) views that could affect deterrence, and international norms.

Military balance facets unique to the space domain

In the space domain, assessing the military balance is difficult for several reasons. First, the military balance is dynamic and changing. Second, the deterrence literature is unclear on whether the local or global military balance matters more for potential attacks in space. Third, different types of weapons could be used against a variety of targets, affecting whether the attack is reversible, attributable, or lethal.

Military balance of power. The current global military balance of power may favor the US, but as China’s military presence in space increases, the US balance of power in space could degrade.

Offensive military doctrine. Space could be considered an offensive-dominant domain, which could encourage one side to act first to gain an advantage. Even if this “first mover” advantage is temporary, striking first could create decisive opportunities in other warfighting domains. Given the nature of the space domain and China’s Active Defense strategy, we predict that the potential first mover advantage offered by attacks in space could decrease the potential effectiveness of US deterrence vis-à-vis China. However, as low Earth orbit constellations proliferate, these more redundant systems could mitigate the first mover advantage.

Ambiguity of intentions in space. US and PRC space policies remain ambiguous about whether they would pursue kinetic attacks against satellites in orbit. This uncertainty about intentions could make deterrence difficult. The lack of specificity regarding intentions also makes effective signaling a challenge, and most scholars believe that effective signaling is a necessary component of a successful deterrence strategy. US and PRC ambiguity regarding their counterspace intentions could lead to inadvertent escalation.

Prevalence of uncrewed systems. The dominant employment of uncrewed systems in space likely reduces the effectiveness of deterrence. Attacks against uncrewed systems may be viewed as having fewer costs because of their lower escalatory potential.

Challenger (PRC) views

Writings on deterrence, especially those informed by prospect theory, indicate that challenger views could have an important effect on deterrence effectiveness. To assess how challenger (PRC) views could affect the US’s ability to deter, we examined China’s views on the international status quo, US reliance on space, and China’s growing dependence on space.

China is dissatisfied with status quo balance of power in space. The PRC has publicly expressed dissatisfaction with the current international order, and the PRC’s space narrative parallels its larger narrative regarding the US-China relationship. Given China’s strong sense of grievance with the current international status quo combined with insights from prospect theory, we predict that US deterrence in space could be less effective vis-à-vis the PRC. In short, the PRC may believe that the benefits of changing the current status quo outweigh the potential costs and thus be more willing to take actions that, in the past, would not have been considered.

Space asymmetry. Researchers from the PLA assess that space capabilities play an outsized role distinct from other types of military power and perceive space capabilities as a more usable and effective means of influencing an adversary before conflict or defeating an adversary during wartime. The US is widely considered the leading power in space, and the US military relies heavily on that space architecture. The PRC may view the operational gains from attacking US space assets as worth the escalatory risk given their importance to the US military. In a conflict, the PRC perception of space asymmetry vis-à-vis the US may (counterintuitively) reduce the effectiveness of US deterrence.

Growing PRC dependence on space. Although US dominance in space may make PRC leaders more apt to consider space weapons, the PLA’s own increasing dependence on space could curtail those inclinations. Advancements in China’s space program may make the PRC reluctant to risk its space assets or less willing to engage in escalatory behavior that risks widening a space conflict.

International norms and signaling

The third category of factors relate to how each country views the space domain and how international norms and signaling could affect deterrence effectiveness.

Space as a warfighting domain. Treating outer space as a warfighting domain may diminish the requirement to state explicitly when or how the US would respond to attacks against its space assets. The absence of sovereignty in outer space may also increase the chances of provocative actions in the space domain. Efforts to establish space as a formal warfighting domain exacerbate this likelihood and thus could lessen the chances for successful deterrence.

Weak international norms. In theory, norms could play a role in limiting the use of space weapons. However, norms are unlikely to be agreed upon by the PRC if they are sponsored primarily by the US Thus, we predict that US-led efforts to promote norms in space are unlikely to increase deterrence effectiveness in the short term.

Reassurance. Some academic literature suggests that offering positive inducements to a challenger is the most effective way to avoid conflict. However, given the current state of US-China competition, it is unclear whether positive inducements are feasible.

KEY FINDINGS AND RECOMMENDATIONS

In the current geopolitical climate, deterring all attacks on US space assets may not be a realistic objective. If one uses an expansive definition of attacks, including cyberattacks, then these types of attacks have already occurred. Although the US may be unable to deter the PRC from conducting all types of space attacks, it may be able to deter the PRC from conducting the most escalatory attacks, such as those that produce space debris or result in the loss of human life.

Of the 10 factors that we examined, only 2—the overall military balance and the PRC’s growing dependence on space—are likely to increase the US’s ability to deter China successfully in the space domain.

Despite the potential limitations of deterrence in the space domain, US policymakers could continue to pursue several initiatives, including building the overall resiliency of the space architecture, increasing space domain awareness (SDA), and assessing potential escalatory scenarios to determine US policy responses.

Improve resiliency of US space architecture

The 2022 National Defense Strategy defines resiliency as “the ability to withstand, fight through, and recover quickly from disruption.” Resiliency can play an important role in strategic stability by denying a challenger the ability to gain the upper hand even if that challenger were to undertake a first strike. Resilience of the space architecture could also increase the overall military balance in favor of the US while simultaneously decreasing reliance on any specific component of that system.

Improve SDA capabilities

Better SDA could increase strategic stability by reducing the attribution problem associated with space activities. Anomalies in space could be the result of enemy action, malfunction, or weather. More robust SDA could provide objective data on issues and determine the source of a problem. Attribution allows the US to hold potential adversary actors accountable for any actions to disrupt space assets. Effective SDA could thus enhance space deterrence and reduce inadvertent escalation by allowing the US military (or commercial satellite companies) to identify problems and attribute them accordingly.

Think about specific space deterrence options

US space assets have already been attacked through reversible means, and whether deterrence will be effective in preventing other types of attacks in the future is uncertain. Here we discuss two possibilities for employing deterrence measures in space that could be examined further.

Deterring PRC attacks against missile warning satellites. Missile warning satellites are part of the US nuclear command and control infrastructure. These satellites are also used in the detection of conventional ballistic missile launches, so the PRC may target them to achieve conventional advantage. Therefore, PRC attacks against US early warning satellites, even if intended to degrade US conventional capabilities, may increase nuclear instability. In this case, a declaratory statement promising retaliation against PRC missile warning satellites may increase the effectiveness of deterrence by heightening PRC awareness of the sensitivity of attacking US missile warning satellites.

Deterring debris-producing attacks. Because both the US and PRC are increasingly dependent on space, the PRC may have less motivation to conduct debris-producing attacks. In this case, deterrence may resemble the mutually assured destruction doctrine of nuclear warfare, in which both sides refrain from attacking because of the costs that would be inflicted on each side.