The Legality of Espionage in the Air and in Outer Space During Peacetime

Recently, the United States and Russia made headlines for downing surveillance vehicles. (Rosenzweig-Ziff, The Washington Post; Gordon et. al., WSJ). In early February, the United States Air Force shot down a Chinese reconnaissance balloon that traveled from Alaska through the continental United States. (Strobel, WSJ). Although China denied using the balloon for surveillance purposes, U.S. officials point out that the balloon had intelligence equipment and claim the balloon was flying at an altitude classified as “near space,” which has significant military and strategy implications. (Heintschel von Heinegg, West Point). This incident was soon followed by reports of a Russian fighter jet colliding with and destroying a United States drone being used for surveillance. (Rosenzweig-Ziff, The Washington Post). Russia has denied responsibility and it is unconfirmed whether Russia intentionally or mistakenly caused the collision; however, both of these events raise questions about the legality of espionage in airspace. (Id.; Olson et. al., NPR). 

While both incidents involve suspected spying, two major differences exist between them. The first is that Russia is currently involved in an armed conflict with Ukraine and China is in a time of peace. (BBC). The second is the location of the vehicle during surveillance. In one case, the Chinese balloon was flying through the territorial airspace of the United States. (Tingley, Space.com). In the other case, the United States surveillance drone was flying in international airspace when the Russian fighter jet collided with it. (Martin, Bloomberg). This distinction is important because Article I of the Chicago Convention on International Civil Aviation (the “Chicago Convention”) dictates that “every State has complete and exclusive sovereignty over the airspace above its territory.” (Chicago Convention). This exclusive territory includes the airspace above both the State’s land areas and territorial waters extending twelve nautical miles from the State’s baseline (typically the coastal low-water line). (Id. at Article II; Article 3, 5, UNCLOS). Conversely, airspace over the high seas is considered international airspace and is not subject to State sovereignty. (ICAO). Similar to international airspace, Article II of the Outer Space Treaty prohibits “national appropriation” of outer space by claims of sovereignty. (Article II, OST). 

These differences are particularly important because the vertical delineation between outer space and airspace is not fully defined. (Dobrijevic, Space.com; NASA). One common articulation of the boundary is the Karman line, or an altitude of 100 kilometers (60 miles). (Id.) However, others prefer to define it as beginning at an altitude of 80 kilometers (50 miles) above mean sea level on Earth. (Id.) Similar to the boundaries themselves, the legality of reconnaissance in airspace and outer space is ambiguous.

Before analyzing the legality of espionage, it is important to note that views differ depending on whether States are in a time of war or peace. The International Humanitarian Law (IHL) neither declares espionage in times of armed conflict illegal nor condones the practice; however, the IHL has defined espionage in times of armed conflict, although specific methods of gathering information are not identified or prohibited. (Hernandez, The Treaty Examiner; Fang et. al., Just Security). Rather, whether espionage is legal during times of war mainly centers on whether the information was attained under false pretenses. (Fang et. al., Just Security). While some international law on wartime espionage exists, there is a complete lack of authority on whether peacetime espionage is legal. (Navarrete et al., Cornell International Law Journal pgs. 899). The current majority view is that espionage is not prohibited under international law because there is no clear rule prohibiting espionage between States, even in times of peace. (Dubuisson et. al., Oxford Bibliographies). However, others contest this viewpoint by holding the view that espionage activities constitute an infringement of sovereignty, which ultimately violates the principle of nonintervention (the right of every sovereign State to conduct its affairs without outside interference). Id. 

At this time, peacetime espionage is also generally unregulated even though it is widely used because most States view espionage “as a vital necessity in the national security process.” (Navarrete et al., Cornell International Law Journal pgs. 898-99). Given these considerations, the current legal status of espionage remains ambiguous because it has neither crystallized into customary international law nor is it codified in a treaty. (Id. at 899; Hernandez, The Treaty Examiner). While some scholars try to argue that espionage is legal under customary espionage exceptions, for a custom to crystallize in international law, there must be both State practice and opinio juris (a belief by the State that it has a binding legal obligation). (Id. at 901; North Sea Continental Shelf Case, ICJ). 

As previously stated, a State has “complete and exclusive sovereignty over the airspace above its territory." (Article I, Chicago Convention). As such, an aircraft cannot fly through territorial airspace without permission, a principle that most States acknowledge and accept. (Cornthwaite, Cornell International Law Journal pgs. 512-15). The principle of sovereign airspace has also been recognized as customary international law by the International Court of Justice and as such is applicable to all States. (Id. at 513; Brittanica). While airspace sovereignty may allow States to limit espionage within territorial airspace, there is no treaty or custom that overtly limits peacetime espionage within territorial airspace, international airspace, or outer space. (Hernandez, The Treaty Examiner pg. 934; Navarrete et al., Cornell International Law Journal). Although the international law principle of nonintervention asserts that States cannot use their territory to interfere with other States’ rights, some scholars take the view that surveillance by a spying State on the territory adjacent to a spied-upon State does not infringe on State sovereignty. (Cornthwaite, Cornell International Law Journal pg. 504). 

As it pertains to custom particularly, State practice is inconsistent and States do not appear to have stated a belief that espionage is legal and therefore, lack the opinio juris requirement for espionage to crystallize into custom. (Navarrete et. al., Cornell International Law Journal pgs. 934, 952; Hernandez, The Treaty Examiner). While States have discussed espionage in outer space, there has not been a specific articulation by States that it is legal; rather, States have focused more on whether or not espionage comports with the Outer Space Treaty requirement that “the moon and other celestial bodies. . . be used. . . exclusively for peaceful purposes.” (Id. at 932-34; Article IV, OST). Therefore, under a strict analysis of the crystallization of custom, neither air law nor space law meets the state practice or opinio juris requirement for espionage to crystallize into custom. (Navarrete et. al., Cornell International Law Journal pg. 952; Hernandez, The Treaty Examiner).

While peacetime espionage and the prevention of it may not be expressly legal, it is also not expressly illegal either. (Navarrete et. al., Cornell International Law Journal pg. 899; Hernandez, The Treaty Examiner). An International Court of Justice Case, The Case of the S.S. Lotus, articulated a famous principle in international law- that what is not explicitly prohibited under international law is permissible. (SS Lotus, ICJ). This therefore places espionage in a gray area of international law and leaves open the question as to whether it will become legal or illegal in the future either through crystallization into customary international law or codification in a treaty.