Space weapons and the risk of nuclear exchanges

The 1967 Outer Space Treaty banned weapons of mass destruction in orbit, but it also established that space would be free for all states to use in accordance with international law (including the UN Charter). The Cold War superpowers interpreted the treaty as legitimating and protecting the use of satellites for early warning, crisis communication, verification, and other activities contributing to deterrence stability—but not for aggression.

In recent decades, however, as space-based reconnaissance, communication, and targeting capabilities have become integral elements of modern military operations, strategists and policy makers have explored whether carrying out antisatellite attacks could confer major military advantages without increasing the risk of nuclear war. In theory, the answer might be yes. In practice, it is almost certainly no.

Hyping threats. No country has ever deliberately and destructively attacked a satellite belonging to another country (though nations have sometimes interfered with satellites' radio transmissions). But the United States, Russia, and China have all tested advanced kinetic antisatellite weapons, and the United States has demonstrated that it can modify a missile-defense interceptor for use in antisatellite mode. Any nation that can launch nuclear weapons on medium-range ballistic missiles has the latent capability to attack satellites in low Earth orbit.

Because the United States depends heavily on space for its terrestrial military superiority, some US strategists have predicted that potential adversaries will try to neutralize US advantages by attacking satellites. They have also recommended that the US military do everything it can to protect its own space assets while maintaining a capability to disable or destroy satellites that adversaries use for intelligence, communication, navigation, or targeting. Analysis of this sort often exaggerates both potential adversaries’ ability to destroy US space assets and the military advantages that either side would gain from antisatellite attacks. Nonetheless, some observers are once again advancing worst-case scenarios to support arguments for offensive counterspace capabilities. In some other countries, interest in space warfare may be increasing because of these arguments.

If any nation, for whatever reason, launched an attack on a second nation's satellites, nuclear retaliation against terrestrial targets would be an irrational response. But powerful countries do sometimes respond irrationally when attacked. Moreover, disproportionate retaliation following a deliberate antisatellite attack is not the only way in which antisatellite weapons could contribute to nuclear war. It is not even the likeliest way. As was clearly understood by the countries that negotiated the Outer Space Treaty, crisis management would become more difficult, and the risk of inadvertent deterrence failure would increase, if satellites used for reconnaissance and communication were disabled or destroyed.

But even if the norm against attacking another country’s satellites is never broken, developing and testing antisatellite weapons still increase the risk of nuclear war. If, for instance, US military leaders became seriously concerned that China or Russia were preparing an antisatellite attack, pressure could build for a pre-emptive attack against Chinese or Russian strategic forces. Should a satellite be struck by a piece of space debris during a crisis or a low-level terrestrial conflict, leaders might mistakenly assume that a space war had begun and retaliate before they knew what had actually happened. Such scenarios may seem improbable, but they are no more implausible than the scenarios that are used to justify the development and use of antisatellite weapons.

Reducing danger. One way to moderate the nuclear risks associated with antisatellite weapons is to realistically assess arguments that attacking satellites would be an easy way to achieve major military advantages without creating unanticipated or uncontrollable consequences. For example, unclassified analysis by Jaganath Sankaran, a research scholar at the Center for International and Security Studies at Maryland, suggests that the practical limitations of Chinese ballistic missiles and launch facilities would make it much harder for China to attack critical US satellites during a crisis than it would be for Washington to respond in ways that denied Beijing any military advantage from such an attack. As more such studies are conducted and given serious consideration, policy makers will be less likely to invest heavily in antisatellite capabilities or to take pre-emptive action against purported antisatellite threats.

Another important way to reduce risk is to strengthen both the norms and the legal rules that protect satellites. The most straightforward way to accomplish this would be to prohibit using anything, including other space objects, to damage or destroy satellites that are not themselves being used as space weapons; and to prohibit any testing of methods for damaging or destroying such satellites. Currently, the biggest threat to established norms and legal protections comes from people who cite anticipatory self-defense—during a crisis or at the outset of hostilities—as a justification for disabling or destroying satellites, launch facilities, or ground stations. Almost as dangerous are those who argue that, once war begins, anything in space becomes fair game and therefore should be targeted. Although it might be legal in the midst of a war to attack satellites used for command, control, communications, and intelligence, it doesn't follow that attacking satellites would be smart strategy.

Voluntary measures for transparency and confidence-building could also help reduce risk somewhat. For example, improving the space situational awareness of all space actors would lessen the risk that nations will blame the wrong party for damage to their satellites or mistakenly conclude that their satellites have been attacked when they have malfunctioned for other reasons. Only a few major spacefaring powers have capabilities for space object detection, tracking, and cataloging—that is, identifying a space object as either debris or a satellite, and also identifying a satellite's owner and function. These nations' capabilities are widely asymmetrical. Only the United States, which has the most sophisticated capabilities, shares space situational data with other space actors. But it does so in a limited manner. Today's lack of transparency regarding space operations exacerbates mistrust among spacefaring nations. More extensive and more inclusive arrangements for data sharing could help reduce mistrust.

But nuclear risks associated with the increased military use of space can only be significantly reduced through transparency and confidence-building measures if the countries that promote such measures prioritize credible reassurance as much as they emphasize deterrence and defense when they decide how much space-related information to share, or what capabilities to acquire and how to use them. Such nations also must rethink the aspects of their nuclear postures that increase the overall risk of inadvertent deterrence failure. In the end, if all nuclear-armed nations espoused unequivocal no-first-use policies, and maintained very tight managerial control over small arsenals optimized for retaliatory deterrence, it would be much harder to envision the proliferation of antisatellite capabilities leading to a nuclear war that nobody wanted.

Is it correct to argue that antisatellite weapons increase the risk of nuclear war? No.

No nation would launch a nuclear attack because an adversary possessed antisatellite weapons. Rather, it would launch an attack because an adversary evidently intended to stage a massive, strategic attack of its own. In the early stages of a nuclear attack, of course, antisatellite weapons might be used to destroy the other side's systems for command, control, communications, and intelligence. Even so, antisatellite weapons would be tools in a nuclear exchange—not the "reason" for the exchange. (The same is true of nuclear weapons themselves.) The most that can be said about antisatellite weapons and the risk of nuclear war is that, in a crisis, these weapons could complicate the calculations of nuclear weapon states, or figure into a nation's decision to take preemptive nuclear action. But again, antisatellite weapons would not be the "reason" for preemptive action.

For nuclear weapon states that maintain a no-first-use policy—including China—antisatellite weapons could not, by definition, provoke a nuclear attack. If antisatellite weapons were actually used in a crisis, but all countries involved were committed to a no-first-use policy, conflict could still be contained within the conventional arena, without escalation to nuclear war. Nuclear risk increases only if states that contemplate the first use of nuclear weapons are involved. Therefore, what is really dangerous in a crisis is a policy that allows the first use of nuclear weapons—not the existence (or non-existence) of antisatellite weapons.

Furthermore, antisatellite weapons are not even a key element in countries' decisions to adopt policies allowing the first use of nuclear weapons. My point may be clearer if I express it this way: In a world without antisatellite weapons, could all nuclear weapon states be expected to adopt no-first-use policies? The probable answer is no. Whether a nuclear weapon state takes preemptive action in a crisis is determined by the country’s political willingness to use nuclear weapons and its overall military doctrine—not by antisatellite weapons. Thus, to focus on antisatellite weapons is to misunderstand the fundamental problem endangering the world in the nuclear age.

Alert and suspicious. In January 2007, China's Ministry of Foreign Affairs announced that China had conducted an outer space experiment—but some foreign officials and media outlets rejected China's explanation of the event and instead described the experiment as an antisatellite test. No matter what Beijing said, these characterizations continued unaltered. At the same time, arguments emerged that antisatellite weapons could increase the risk of nuclear war.

In 2010, China announced it had conducted a land-based midcourse missile interception technology test. But again, some foreign countries refused to accept China's explanation, and intentionally blurred the lines between missile interception and antisatellite technology. Misconceptions in the international imagination about China's so-called antisatellite weapon program were strengthened.

For China it is thus quite natural to remain alert to, and suspicious of, arguments about antisatellite weapons and the risk of nuclear war. Indeed, China suspects that such arguments are intended only to stigmatize and disrupt China’s outer space program.

From China's perspective, the key factor in space issues is building (or rebuilding) East-West trust. China may be a newcomer to outer space, but it has legitimate rights there, which Western countries must recognize. Otherwise, they hinder their relations with China and other newcomers to outer space. They cause interactions between old and new members of the outer space club to be marred by tension and suspicion. For the United States and China, acknowledging one another's interests in outer space is a necessary foundation for effective communication regarding outer space and other strategic issues.

China is open to dialogue with the United States, and exhibits a positive attitude about engagement with Washington, but the United States doesn't seem to regard strategic engagement with China very positively. Three aspects of US attitudes deserve attention.

First, the United States is in the habit of classifying countries—as allies, as enemies, and so forth. Clearly, China does not fall into the category of US allies. In 2009, after many years of effort, China was able to break through the limitations that Washington's classifications imposed, and the two countries established the US-China Strategic and Economic Dialogue—a mechanism allowing high-ranking officials from both sides to discuss matters of political, economic, and strategic importance. For many years, high-level dialogue between China and the United States was referred to as "senior dialogue" because the United States reserved the term "strategic dialogue" for interactions with allies. But it seems that US attitudes toward the Strategic and Economic Dialogue are still influenced by China's "country classification." Washington appears more sensitive to the negatives than the positives in the bilateral relationship.

Second, the US side severely restricts strategic exchanges with China in fields such as military-to-military relations, outer space cooperation, and high-technology exports. These restrictions attract a lot of criticism within Chinese society and inhibit Beijing's ability to trust the United States.

Third, the United States continues to develop and work toward deployment of a strategic missile defense system within the United States and in countries along China's periphery—though China has repeatedly expressed its concerns about the system's strategic implications for China's nuclear deterrent. Bearing Washington's plans for missile defense in mind, arguments about the destabilizing nature of China's outer space program seem even less convincing.

If one wishes to moderate the risk of nuclear war, antisatellite weapons should not be a primary focus. An exchange of viewpoints on a host of other issues could do more to reduce strategic suspicions and moderate nuclear risk. From China's perspective, linking nuclear war with antisatellite weapons only indicates that Western countries want to limit China's program in outer space. This does nothing to reduce nuclear risk. Perhaps exchanges such as this roundtable, in which parties from various sides explain, clarify, and elaborate their positions on strategic issues, can help reduce misunderstandings, misinterpretations, and miscalculations.

China's 2007 antisatellite test sparked considerable debate among policy planners in the United States regarding the potential vulnerability of US space assets. Many scholars and analysts believe that, over the last decade, China has slowly but steadily invested in a wide range of counterspace capabilities that are in fact capable of posing threats to the United States and its allies. Concern focuses on two issues.

First, Chinese counterspace abilities might someday challenge US command of the commons, particularly in the area of space. This is a crucial consideration vis-à-vis Washington's conventional military operations because space assets provide the United States enormous advantages in military surveillance and other areas. Second, certain counterspace capabilities could endanger assets that are critical to Washington's launch-on-warning nuclear posture. An attack on such assets could lead to an inadvertent nuclear war. Relatedly, some worry that Beijing’s investments in counterspace technologies might trigger a regional arms race—in particular, Delhi might invest in such capabilities as well, heightening the risk of an inadvertent nuclear exchange between India and China.

Postures and motivations. The US military enjoys significant qualitative advantages over potential rivals because of support provided by space platforms. A vast array of imaging satellites, for example, significantly improves US surveillance capabilities. Global positioning satellites help US forces guide their weapons with unparalleled accuracy. Communication satellites help control flows of information. As a result, US military forces are able to project power in an expeditionary manner. They can operate in distant theaters, employing both doctrines and sophisticated equipment that rely on satellites for advanced surveillance, reconnaissance, communication, navigation, and timing data.

But US space assets also represent potential vulnerabilities—mainly to Chinese counterspace capabilities. Several assessments based on publicly available information suggest that, despite China’s increased investments in counterspace technologies, Washington still enjoys a huge advantage in conventional operations conducted with the support of space assets. Still, China is reluctant to engage fully in the rules-based world order that Washington built after World War II, and this is a key concern to US policy makers. They worry that China might exhibit unpredictable behavior—and indeed, unpredictability was manifested in the antisatellite weapon test that China carried out in 2007, and in its other tests in outer space since then.

A second key concern for US policy makers is that counterspace capabilities might inadvertently trigger a nuclear exchange—say, between the United States and China, or between China and India. Several US policy planners worry that China could employ counterspace capabilities to destroy Washington's critical space assets, such as early warning satellites. In some scenarios, this could lead to incorrect conclusions that China had engaged in a preemptive nuclear strike. Similarly, Chinese or Indian investments in these capabilities might lead to miscalculations in Beijing or Delhi, escalating a conflict into a nuclear exchange. But to understand the probability of such a situation, it is important to understand China and India's motivations for acquiring counterspace capabilities—and also to understand the two countries' nuclear postures.

Unfortunately, China's motivations regarding its counterspace capabilities remain unclear. Does China contemplate degrading US command of the commons in order to hinder the operational capability of US forces in the Western Pacific? Does Beijing envision eliminating US nuclear surveillance capabilities? These critical questions remain unanswered. Even more confusing to policy makers is whether China will approach these issues in the same way that Moscow did during the Cold War—in that era, the Soviet Union and the United States diminished pressure and reassured themselves by establishing treaties such as the Outer Space Treaty. One thing is certain: China’s current counterspace capabilities are sufficient to deny the United States access to space—but only temporarily.

When it comes to nuclear posture, the situation is clearer: China does not believe in conducting a nuclear first strike. From 1964, when China conducted its first nuclear test, until the mid-1990s, when negotiations for the Comprehensive Nuclear Test Ban Treaty began, the modernization of the Chinese arsenal moved at a snail’s pace. In the late 1970s, China developed long-range ballistic missiles capable of targeting the continental United States, but Beijing possessed barely a dozen such missiles. For the Chinese, even a warhead ratio such as 125:1 in Washington's favor seemed sufficient to provide nuclear deterrence. And unlike the United States, which developed an arsenal that included several thousand warheads and delivery systems, diverse nuclear warfighting capabilities, and baroque redundancies, China kept its arsenal simple. Beijing forsook the technical for the political.

Today, all available evidence suggests that China, though its nuclear arsenal has grown, has not fundamentally rethought its posture. Hence it is very unlikely that China conceives of antisatellite weapons as a means for disabling nuclear surveillance satellites. And even if China did not espouse a no-first-use policy, Beijing's nuclear delivery systems are not particularly accurate. They are incapable of executing the sort of "splendid first strike" that might eliminate US land-based nuclear forces.

Despite tensions between China and India, Delhi's nuclear posture vis-à-vis Beijing is rather relaxed—it is based on minimum deterrence and a strict no-first-use policy. Indian national security managers, like their Chinese counterparts, see nuclear weapons as political tools, and they have resisted efforts by military planners to jettison no-first-use. India possesses approximately 100 nuclear warheads, but none are mated with missiles under normal conditions. Indian policy planners, because of their country's strong commitment to no-first-use, have little incentive to develop an operational antisatellite weapon to help execute a first strike against China. Such ideas hardly figure in any Indian public forum about space security. Rather, most debates center around defending India’s growing space assets in low Earth orbit.

To be sure, China’s successful demonstration of an antisatellite weapon galvanized a debate in India, and prompted the Defense Research and Development Organisation to begin exploratory efforts toward developing retaliatory capabilities and an Indian antisatellite weapon. But India’s antisatellite research efforts, unlike China's, have emerged from a national missile defense program, which suggests it is largely an offshoot of that program. Many kinetic energy antisatellite technologies overlap with the ballistic missile defense system currently under development in India, especially in the areas of radar tracking and target acquisition. The little publicly available evidence suggests that the Indian authorities have not instituted an antisatellite program. Even if Delhi did so, India’s antisatellite weapon technology is largely unproven; not a single test has been conducted. In contrast, the United States conducted almost three dozen tests, and the former Soviet Union about two dozen, before declaring their antisatellite weapons operational.

If the United States is worried that Chinese advances will erode its primacy in space, evidence suggests that Chinese systems are at least capable of challenging US primacy. But concerns that Chinese or Indian advances in counterspace technologies will trigger an inadvertent nuclear exchange are overstated. Chinese and Indian counterspace capabilities have not advanced far enough to destroy US early warning satellites—and, on a more fundamental level, India and China's nuclear postures remain oriented toward deterrence.