Chow concludes that “the United States as well as other nations should forewarn any party that positioning space stalkers for surprise attack would be treated as an aggressive act and the perpetrator considered an aggressor. Once this position is clearly defined in peacetime, existing and developing defense measures then will have the necessary warning time to defeat the space stalkers and protect the threatened satellites.”
This approach starts from two basic principles. First, once a space object is in orbit, one cannot reliably distinguish a space stalker from an ordinary satellite, especially a spacecraft providing satellite service or a space debris clearer like China’s Aolong-1. Second, routine space operations could bring one or even a few space objects close to another country’s satellites at the same time. These occurrences cannot be prohibited and must be accommodated.
From there, Chow sets out guidelines for a preemptive self-defense approach that draws inspiration from parts of the UN Convention on the Law of the Sea. Namely, Chow proposes that satellites be given contiguous zones (measured by 148 kilometers, but actual size to be determined by the Defense Department) from which they can punish dangerous infringements, while still allowing other satellites innocent right of passage. To differentiate between the two, Chow suggests that the Space Security and Defense Program and National Intelligence Office establish a threshold for the number of satellites another country can place within the contiguous zones of U.S. satellites before triggering a preemptive self-defense response. For example, if the United States set the threshold number at four, and five American satellites were being simultaneously stalked by Chinese counterparts, “the United States can plan to use preemption as the last resort.”
There are mainly advantages to a preemptive self-defense approach. First, it protects against the most damaging attacks, which would come from a knockout blow against many U.S. satellites simultaneously. Secondly, it should be able to gain international support, because there is no legitimate, peaceful reason to tailgate so many satellites from another country. Accordingly, “simultaneously stalking a large number of another nation’s satellites is justifiably treated as hostile intent requiring a last-resort preemption to neutralize such a threat.” Indeed, finding an internationally agreed-upon threshold number would not be in the sole interest of the United States, but also in that of countries like China and Russia, as they’d be protected from America’s own space-stalker capabilities. As Chow argues, “The ultimate purpose of last-resort preemptive self-defense is that it does not actually have to be executed. Therefore, the adversary knowing its space-stalking attack to be futile would not pose a space-stalking threat in the first place.”
Whatever one’s take on Chow’s proposed strategy, the threat he points to is impossible to ignore.
Zachary Keck is a former managing editor of the National Interest . You can find him on Twitter: @ZacharyKeck.