In February 2023, a United States Air Force fighter jet shot down a Chinese high-altitude balloon flying at about 60,000-65,000 feet (18-20 km) altitude in sovereign U.S. airspace. After the event, some commentary suggested that the incident raised questions about the supposedly ambiguous or unsettled legal status of high-altitude airspace, sometimes referred to as “near space.” Later that year, other media reports hinted that China was establishing a “Near Space Command” as a new force within the People’s Liberation Army. Many countries, including the U.S., have sponsored research into the military potential of near space. However, China’s interest in near space is not limited to operational matters; there is a legal aspect to it as well. China’s narrative about near space appears to be an expression of its doctrine of legal warfare. Understanding China’s intent for a legal warfare narrative first requires an understanding of the law as it actually is in the place concerned.
The first article of the Outer Space Treaty (1967) guarantees for all states the right of free access to outer space. This principle of states’ free access to outer space is also recognized as a rule of customary international law. This is why one state’s satellites can move through outer space in orbit above the territory of another state. Moreover, under the Convention on International Civil Aviation (Chicago Convention, 1944), each state exercises sovereign control of the airspace above its territory. This is also recognized as a principle of customary international law.
Although boundaries between air space and outer space exist for administrative purposes, such as establishing the boundary of U.S. Space Command’s area of responsibility at 100 km above mean sea level, there is no internationally agreed demarcation of where air space ends and outer space begins. Moreover, no principle of either treaty law or customary international law recognizes any zone between air space and outer space in which different rules apply. This boundary may not be precisely defined, but it is nonetheless a boundary, not a zone.
However, for more than a decade Chinese writings have suggested that near space is, or should be, a legally cognizable zone with its own rules. In a PLA Daily newspaper article from 2011 titled, “Near Space: A Strategic Resource That Cannot Be Ignored,” Zhang Dongjiang, a researcher at China’s Academy of Military Sciences, suggested that airspace between 20 km and 100 km was a “legal blank that needs to be filled urgently.” Zhang further argued that “it would be beneficial for China to drive the development of rules for use of near space.” At least, that is how an English-language translation of the article puts it; according to Elliot Ji of the Institute for National Strategic Studies, Zhang’s statement in the original Chinese is more suggestive of a competition-focused interest: Zhang says it would be “beneficial for gaining the discourse power (话语权) in setting ‘international game rules’ for [the use of] near space in the future.”
China’s Aerospace Security Strategic Concept (2016) also implies that near space is, or should be, a legally distinct zone. It states, “China should actively advocate and participate in the establishment of the Near Space Security Law and the Space Security Law in order to better carry out air and space exchanges and cooperation, maintain air and space security order and build a harmonious space environment, clarify the rights and obligations of all countries in public space, near space and space and improve the international air and space security laws and regulations guarantee mechanism with the protection of national public space and space interests as the main content.”
When the discovery and disclosure of the February 2023 incursion by a Chinese high-altitude balloon into U.S. airspace forced China to address the legality of its overflight, it did not press its near space narrative beyond the well-understood limits of international law. China asserted (falsely, according to U.S. officials) that the balloon was only a civilian weather balloon and that its intrusion into U.S. airspace was an “unexpected situation caused by force majeure.” Nevertheless, China complained that the U.S. response in shooting down the balloon was “a clear overreaction,” “unacceptable” and “irresponsible.” Media reporting of the incident described it as a near space activity, despite the balloon operating at or below the lowest altitude Chinese writers had previously described as near space. Was China’s official reaction merely face-saving posturing, or a more methodical obfuscation of issues to salvage aspects of its near space narrative? Were media reports associating the balloon incident with near space unintentionally proliferating a People’s Liberation Army (PLA) legal warfare narrative?
A few months after the 2023 balloon incident, there were curious reports that China had established a “Near-Space Command” within the PLA as a force equivalent to the PLA services, responsible for hypersonic weapons as well as high-altitude drones and balloons. Most reporting of the new command pointed to a November 2023 article in the South China Morning Post, which in turn described a paper submitted to the 11th China Command and Control Conference. It now seems clear that the Near-Space Command was never actually established; less certain is the extent to which its reported mandate was ultimately assumed by the PLA Aerospace Force established in 2024, or the extent to which plans for a Near-Space Command reflected official Chinese Communist Party policy at the time. It is not even clear if the paper actually described a new PLA organization as the article suggests, or merely new ways of commanding PLA operations in high-altitude airspace.
The organizational particulars matter less than the legal implications of a force described as operating in a zone between airspace and outer space. Some writers seem to have treated rumors of a Near-Space Command as ipso facto calling into question the sufficiency of long-established principles of air and space law. For example, Jonathan Ping and Heaven Elishav of Australia’s Bond University suggested in 2024 that “implementation of the Near-Space Command and the newly established Aerospace Force divisions requires a reconsideration of astropolitics to acknowledge that policies and technological realities have surpassed the UN Outer Space Treaty of 1967.” However, there is no reason why an operational concept of near space necessarily suggests anything about legal concepts of air space or outer space.
China’s narrative about near space appears to be an expression of what the People’s Liberation Army calls “legal warfare” (part of its “Three Warfares” doctrine, which includes public opinion warfare, psychological warfare and legal warfare). The Three Warfares are described in the Science of Military Strategy, a publication of China’s National Defense University used to educate senior PLA officers. Principles of “legal warfare” described in the 2020 edition of the Science of Military Strategy (the latest for which English translation is available) include:
China’s sustained narrative about near space in both legal and technical contexts conforms to each of these aspects of legal warfare.
What are appropriate responses to China’s near space legal warfare narrative? First, it is important to call it what it is: an expression of the PLA’s doctrine of legal warfare. When China-aligned sources refer to near space it normalizes the notion that there is a place between air and space in which the rules differ from those of the adjacent domains. This is not true under current law. Is this narrative a knowing misstatement of law, intended as a pretext of legitimacy for Chinese incursions into other states’ sovereign airspace? Is it part of an effort to propose a new rule of international law in which near space is a legally distinct place? Is it merely designed to sow confusion and distrust in existing principles of international law? Perhaps, it serves all these purposes. Whatever the purpose, by recognizing legal warfare in China’s near space narrative, the flaws, fallacies and errors it propagates become apparent.
Second, the term near space should probably be avoided entirely. It has no legal significance as a place, since under international law airspace extends all the way to where outer space begins. Significant activities can occur in airspace or outer space at any distance from Earth’s surface: all space launches transit the full limit of airspace before reaching outer space, as do ballistic missiles and some hypersonic missiles. However, no particular strategic insight or legal clarity is gained through usage of the term near space. “High altitude airspace” or “very low Earth orbit” (as appropriate) suffices, with clarity as to which domain’s distinct legal regime applies.
Third, the common attributes of China’s near space legal warfare narrative and its better-known unlawful actions in the South China Sea should be highlighted. Each illustrates the problems associated with the other. Each involves China asserting a contrived boundary under international law (the so-called “nine-dash line,” in the South China Sea). China seems to view its legal warfare in each case as providing a pretext of legitimacy for unlawful activities there. Each is characterized by a Chinese narrative expressed consistently over time, and by gradual escalation in the severity of unlawful Chinese actions. These are the hallmarks of a deliberate policy. China’s approach to the South China Sea has predictive value for what China is likely to do in other places of emerging strategic importance, such as the high-altitude airspace it calls near space.
That China is relying on a legal warfare approach to what it calls near space is telling. High-altitude airspace surely is a “strategic resource that cannot be ignored,” but states have an important interest in preserving sovereign control over the airspace over their territory and territorial seas. In other words, they have an important interest in countering China’s near space legal warfare.
Todd Pennington is the Senior Research Fellow for Space Strategy and Policy at National Defense University’s Institute of National Strategic Studies. He is a retired U.S. Air Force colonel who previously served as a legal advisor for DoD space programs with OSD, U.S. Space Command and the U.S. Space Force. Pennington is an affiliate fellow with the Georgetown Law Center on National Security, and an adjunct professor of law at Georgetown. The views expressed here are the author’s and do not necessarily reflect the official policy or position of the National Defense University, the Department of Defense, or the U.S. Government.
Emmy Kanarowski is a senior at Cornell University majoring in Science and Technology Studies and in Information Science. She recently completed a research internship at National Defense University’s Institute of National Strategic Studies.
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