The Outer Space Treaty keeps weapons of mass destruction out of orbit. That's not the same as prohibiting warfare in space. Some nations have successfully tested destructive antisatellite weapons in space and many more are presumed to possess antisatellite capabilities. Meanwhile, important strategic capabilities such as early warning, secure communications, intelligence gathering, and command and control increasingly run through space. This raises the troubling possibility that the use of antisatellite weapons amid a crisis between nuclear-armed nations might lead to a nuclear exchange—indeed, US war games have repeatedly demonstrated that antisatellite weapons can cause crises to escalate in unpredictable ways. Below, experts debate this question: To what extent do antisatellite weapons increase the risk of nuclear war—and what can be done to moderate the risk?
Much ado about nothing
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.