International Law v. “International Practice”: Critiquing the American Response to Unmanned Flying Objects Over United States Territory

International Law v. “International Practice”: Critiquing the American Response to Unmanned Flying Objects Over United States Territory

Funsho Delé Nwabuzor

The recent international incident regarding the purported Chinese spy balloon that flew over United States territory has been closely watched and commented on by international news media organizations and even other authors in this journal. There remain debates, however, regarding the height to which airspace remains sovereign over the land or sea territory of a particular State.[1] While there is general agreement that sovereign airspace extends up to and through the height at which commercial aircraft fly, it is well settled that jurisdiction over airspace does not extend to space.[2]

Under the Chicago Convention, “each State has complete and exclusive sovereignty over the airspace above its territory…sovereignty [that] cannot be delegated.”[3] However, each State can delegate the functional responsibilities of air traffic management systems to regional authorities, for instance.[4] Such regional management systems are obviously advantageous in regions where many States are in close geographic proximity and there is a high density of air traffic.[5]

Pursuant to U.S. federal regulations, the Federal Aviation Administration (“FAA”) has created “Air Defense Identification Zone[s]” over the United States’ territorial land and water.[6] In such zones, all aircraft are required to identify themselves (excepting U.S. Department of Defense and legitimate law enforcement crafts) on grounds that national security requires it.[7] “Light” unmanned free balloons—defined as having a payload of “combined mass of less than 4 kg,” with certain exceptions qualifying such balloons as “heavy”[8]—must  receive the authorization of the State “from which the launch is made”[9]; thus, if the purported spy balloon did originate in China, then Chinese authorities should have been aware not only of its origins but also of its nature. While “light” balloons used for meteorology need not seek approval from States over which they operate, balloons which meet the definition of “medium” or “heavy” still must seek authorization from the States over which they fly.[10]

While U.S. Secretary of State Antony Blinken denied claims by Chinese authorities that the United States has flown spy balloons over China at least ten times,[11] absent from official U.S. government statements was acknowledgment of the fact that the United States uses and has used balloons and unmanned drones to spy on other States without their authorization.[12] During the Cold War, the United States routinely sent spy aircraft over Chinese territory without their authorization.[13] While the United States could adopt a “that was then, this is now” attitude, news media should not so easily dismiss Chinese claims that the United States has recently surveilled their territory using unmanned spy balloons. After all, the United States used over sixty aerostats (essentially, spy balloons) to surveil territory in Afghanistan and Iraq after the 2003 invasion of the latter.[14] While it is conceivable that the United States launched such balloons from Iraq, Afghanistan or friendly countries near those States, it is also possible that the United States launched such craft from its own territory and then flew them to Western Asia over other countries without first obtaining explicit authorization.

Indeed, I believe the Biden Administration’s bungled response supports the official Chinese narrative. U.S. government officials repeatedly stated publicly that the Chinese balloon was not a threat, and was incapable of obtaining intelligence beyond what the Chinese either already knew or could obtain from space satellites.[15] U.S. officials later admitted that the Chinese balloon was probably “thousands of miles off course” and that China may never have intended to fly the balloon over the continental United States in the first place.[16] Chinese official statements about the United States overreacting have been lent credence by the United States’ own intelligence agencies’ admission that the balloon’s trajectory may have been in error and posed no threat.[17] An anonymous U.S. government source conceded to Reuters News Agency that the balloon “originally had a trajectory that would have taken it over Guam and Hawaii” but was blown off course by strong winds.[18]

The Chinese official response—that the United States, in shooting down the balloon, overreacted and acted against established “international practice”—should be more carefully considered by U.S. authorities, and the American public, as a prudent observation.[19] Even if a State violates international law, a lack of restraint by the violated party could potentially lead to an escalation of tension, if not conflict. While the United States did recover debris from the Chinese balloon shot down over the Atlantic Ocean, U.S. and Canadian authorities could not even locate the debris from two unidentified objects shot down over Alaska and Lake Huron, and a third over Canada’s Yukon Territory.[20] Regarding the objects brought down after the Chinese balloon, President Biden stated: “[T]he intelligence community’s assessment is that these three objects were mostly balloons tied to private companies, recreation[,] or research institutions studying weather or conducting other scientific research.”[21] Blake Herzinger, of the American Enterprise Institute, wonders “why the [Biden Administration] would sortie fighters and shoot” down objects “without correctly identifying them in the first place.”[22] If the United States wants its overtures about compliance with international law and exercise of restraint to be heeded in conflicts and flashpoints across the globe, the United States needs to lead by example by making rational, restrained decisions, when objects deemed non-threatening cross into, or over, U.S. territory.[23] While the United States very well may be entitled to shoot down such objects under international law, a more nuanced deference to “international practice” may lead to better long-term results.


[1] Donald Rothwell, Did China’s balloon violate int’l law?, Conversation (Feb. 5, 2023, 10:14pm),

[2] Id.

[3] Worldwide Air Transport Conference (ATCONF) Sixth Meeting: Montréal, 18 to 22 March 2013, § 3.1 (Int’l Civ. Aviation Org., Working Paper No. ATConf/6-WP/80, 2013).

[4] See id.

[5] Id.

[6] Federal Aviation Administration, ENR 1.12, 1.4.1 (Nov. 3, 2022),

[7] See id. at 1.3.1.

[8] See Int’l Civil Aviation Org. [ICAO], Int’l Standards: Rules of the Air Annex 2 Convention on Int’l Civ. Aviation, at app. 4-1, §§ 1(a)-(c), 2.1-2.2 (10th ed. July 2005).

[9] Id.

[10] Id.

[11] Leila Fadel, Barrie Hardymon & Nina Kravinsky, Blinken has a lot on his plate including tensions with China & the war in Ukraine, NPR (Feb. 14, 2023),

[12] John Delury, Spy Balloons Evoke Bad Cold War Memories for China: Covert U.S. intrusions into Chinese airspace were common for decades., Foreign Pol’y (Feb. 13, 2023),

[13] Id.

[14] See Sentinels of the Sky: The Persistent Threat Detection Sys., Lockheed Martin, (last visited Mar. 12, 2023).

[15] See Tom Vanden Brook, DOD did not think the spy balloon was a military threat when it was first detected, USA Today (Feb. 6, 2023),

[16] See Transcript by Juana Summers, Militaries have sought to use spy balloons for centuries. The real enemy is the wind, NPR (Feb. 17, 2023),,balloons%20losing%20to%20the%20wind.

[17] See Howard W. French, The U.S. Overreacted to the Chinese Spy Balloon. That Scares Me., Foreign Pol’y (Feb. 13, 2023),; see also Brittany Bernstein, Chinese Spy Balloon May Not Have Been Intended to Fly over Continental U.S., Report Says, Nat’l Rev. (Feb. 15, 2023),

[18] See Downed Chinese balloon aimed for Hawaii but was blown off course – U.S. official, Reuters (Feb. 16, 2023),

[19] See David Shepardson & Yew Lun Tian, U.S. imposes security zone in search for Chinese balloon remnants, Reuters (Feb. 6, 2023),

[20] See Faris Tanyos, U.S. ends search for 2 unidentified objects shot down over Alaska, Great Lakes, CBS News (Feb. 17, 2023),

[21] See Faris Tanyos, U.S. ends search for 2 unidentified objects shot down over Alaska, Great Lakes, CBS News (Feb. 17, 2023),; see also Andrew Jeong & Kyle Rempfer, U.S., Canada suspend search for objects shot down over Alaska, Lake Huron and Yukon, Wash. Post (Feb. 18, 2023),

[22] Andrew Jeong & Kyle Rempfer, U.S., Canada suspend search for objects shot down over Alaska, Lake Huron and Yukon, Wash. Post (Feb. 18, 2023),

[23] See U.S. defense chief urges China, Japan to exercise restraint, Reuters (Sept. 18, 2012),; see also U.S. urges Turkey to ‘exercise restraint’ in Syria operation, Reuters (Jan. 21, 2018),