Written by Lara Maluf-Mas

I. Introduction

In 1944, the Convention on International Aviation (“Convention”)¹Convention on International Civil Aviation, Dec. 7, 1944, 61 Stat. 2241, 15 U.N.T.S. 295 [hereinafter Chicago Convention]. established the framework for international aviation law and the International Civil Aviation Organization (“ICAO”).²See Convention on International Civil Aviation – Doc 7300, Int’l Civ. Aviation Org., https://www.icao.int/convention-international-civil-aviation-doc-7300 (on file with American University International Law Review) (last visited Oct. 16, 2025) (noting that the ICAO became a specialized agency of the United Nations in October of 1947). The ICAO, composed of 193 member states,³About ICAO, Int’l Civ. Aviation Org., https://www.icao.int/about-icao (on file with American University International Law Review) (last visited Oct. 16, 2025). develops standards and procedures for international civil aviation.⁴See Vision and Mission to 2025, Int’l Civ. Aviation Org., https://www.icao.int/vision-and-mission-2025 (on file with American University International Law Review) (last visited Oct. 16, 2025) (noting that the ICAO also undertakes compliance audits, performs studies, analysis, and assists its member states and stakeholders).

The ICAO draws a strict distinction between civil and state aircraft: while civil aircraft must oblige by ICAO rules,⁵Chicago Convention, supra note 1, arts. 3(a), 4. state aircraft⁶See Chicago Convention, supra note 1, art. 3(b) (defining state aircraft as aircraft used in military, customs, and police services). are only required to operate with due regard for civil aircraft in international airspace.⁷Chicago Convention, supra note 1, art. 3(d); see also Michel Bourbonniere & Louis Haeck, Military Aircraft and International Law: Chicago Opus 3, 66 J. Air L. & Com.  885, 894–95 (2001) (discussing how parties to the Chicago Convention must promulgate within their regulatory structures the obligation for state aircraft to operate with due regard for civil aircraft). As such, members of the Convention must ensure through their regulatory frameworks that state aircraft do not endanger the safety of civil aircraft.⁸See Chicago Convention, supra note 1, art. 3(d) (“The contracting States undertake, when issuing regulations for their state aircraft, that they will have due regard for the safety of navigation of civil aircraft.”); see also Bourbonniere & Haeck, supra note 7, at 894–95 (stating that the due regard obligation requires state aircraft to operate with due regard for the navigation of civil aircraft). This state-aircraft exception, and diversified military regulations by member states, has fueled increasing tensions over the legality of military and reconnaissance operations within flight information regions (“FIRs”) and disputed airspaces.⁹International Civil Aviation Organization [ICAO] European and North Atlantic Office, Interim Guidance Material on Civil/Military Cooperation in Air Traffic Management, at 27, EUR Doc. 032 (1st ed. 2015) (on file with author) [hereinafter Interim Guidance Material] (“This leaves it up to the individual State to regulate these operations and services, generating a wide diversity of military regulations. However, especially in congested airspace, harmonized regulation is a precondition for a safe, efficient and ecologically sustainable aviation system.”); Bourbonniere & Louis Haeck, supra note 7, at 887 (explaining the need for minimum civil-military safety aircraft regulation); see infra Part IV.  

II. Legality of State Aircraft in Flight Information Regions

FIRs are zones of international airspace in which ICAO member states provide air traffic services for incoming aircraft.¹⁰Flight Information Region (FIR), SKYbrary Aviation Safety, https://skybrary.aero/articles/flight-information-region-fir (on file with American University International Law Review) (last visited Oct. 17, 2025) (explaining that the ICAO divides global airspace into nine navigation regions with FIRs in each). These states enforce civil and commercial regulations and standards adopted by the ICAO.¹¹Id. Exclusive economic zones (“EEZs”) are maritime zones extending up to 200 miles past a state’s sovereign coastline.¹²See What is the “EEZ”?, Nat’l Oceanic & Atmospheric Admin. (July 29, 2020), https://oceanexplorer.noaa.gov/ocean-fact/useez (on file with American University International Law Review) (last updated Jan. 6, 2023) (noting that the concept of the EEZ was adopted in the 1982 Convention on the Law of the Sea). The coastal state has the right to extract natural resources within the area and regulate its economic activity; however, the airspace above an EEZ is subject to international law.¹³See id. (stating that coastal states have sovereign rights for exploring, exploring, conserving, and managing natural resources of the seabed, subsoil, and waters above it, and other rights and duties subject to international law); U.N. Convention on the Law of the Sea, art. 58, Dec. 10, 1982, 1833 U.N.T.S. 397 (all States have freedom of navigation, overflight, and lawful uses of the sea related to these freedoms in economic exclusive zones).

III. American Legal Doctrine on Due Regard

The United States requires that all state aircraft comply with ICAO procedures when operating in international airspace when practicable; however, certain state aircraft operations satisfy the due regard obligation through onboard technologies and self-guidance.¹⁴U.S. Dep’t of Def., Instr. 4540.01: Use of International Airspace by U.S. Military Aircraft and for Missile and Projective Firings ¶¶ 2(e)(1)–(2) (June 2, 2015) [hereinafter Instr. 4540.01]. The Department of Defense requires that state aircraft operate with due regard in international airspace by flying under visual meteorological conditions or using radar surveillance.¹⁵See id. ¶¶ 3(c)(1)(a)–(c) (stating requirements for state aircraft operating sensitive missions). Thus, certain state aircraft operating sensitive missions may disregard the instructions of air traffic control (“ATC”) and maintain responsibility for their own safe separation.¹⁶Id.: see also State Aircraft and ‘Due Regard’ Operations ¶ 2.6.1.3 (Tech. Operations Comm. & Pro. and Legal Comm. Working Paper, Paper No. 92, 2018) (explaining that for missions incompatible with civil aviation rules, state aircraft may ignore controllers’ clearance and instructions).

IV. The Divide of the State’s Obligations When Practicing Due Regard

Disputes arise when states have differing obligations for operating with due regard under their customary laws.¹⁷Interim Guidance Material, supra note 9, at 27; see Eve Massingham, Radio Silence: Autonomous Military Aircraft and the Importance of Communication for their Use in Peace Time and in Times of Armed Conflict under International Law, 1 Asia-Pacific J. Int’l Humanitarian L. 198–99 (2020) (discussing the need for further clarification on state aircraft requirements to avoid conflicts considering advancing technology, such as autonomous aircraft); see infra Part IV. Although the U.S. has interpreted due regard to allow for state aircraft to operate independently of civil aviation controllers, some states have asserted additional procedural requirements.¹⁸See Doyle Hodges, Back to Basics in the South China Sea, Lawfare (Apr. 13, 2016), https://www.lawfaremedia.org/article/back-basics-south-china-sea (on file with American University International Law Review) (noting that China interprets due regard as prohibiting foreign military operations within their EEZs, a position that the U.S. military does not accept); Ashley S. Deeks, Downing of US drone in Russian Jet Encounter Prompts Counterclaims of Violations in the Sky – an International Law Expert Explores the Arguments, Conversation (Mar. 15, 2023), https://theconversation.com/downing-of-us-drone-in-russian-jet-encounter-prompts-counterclaims-of-violations-in-the-sky-an-international-law-expert-explores-the-arguments-201857 (on file with American University International Law Review) (noting that Russia accused the U.S. drone of flying towards Russian territory with its transponder off and causing suspicion of the aircraft).

In March 2023, a U.S. MQ-9 Reaper drone was intercepted by two Russian Su-27 jets before crashing into the Black Sea.¹⁹See Michael Schmitt, The Russian Interception of the U.S. Reaper and International Law, Just Sec. (Mar. 15, 2023), https://www.justsecurity.org/85494/the-russian-intercept-of-the-u-s-reaper-and-international-law (on file with American University International Law Review) (reporting the U.S. drone was operating an intelligence, surveillance, and reconnaissance mission). The U.S. accused Russia of using unsafe maneuvers in international airspace and preventing the U.S. from exercising its right without interference from other states.²⁰See id. (referring to the Department of Defense’s Law of War Manual, which allows state aircraft to operate in international airspace with due regard and without interference by other States); Russian Jet Strikes U.S. Drone Over Black Sea, Arms Control Ass’n (Apr. 2023), https://www.armscontrol.org/act/2023-04/news-briefs/russian-jet-strikes-us-drone-over-black-sea (on file with American University International Law Review). Russia argued that the drone operated without transponder activation in a designated maritime exclusive zone.²¹See Deeks, supra note 18 (noting that Russia accused the U.S. of operating its drone without transponder activation in an area it designated for special military operations in Ukraine).   Thus, this incident portrays the dichotomy of the U.S. and Russian interpretation of due regard.²²See generally id.; Schmitt, supra note 19 (both sources discussing each state’s argument in the conflict). While the U.S. associated due regard with the freedom of overflight in international airspace, Russia’s interpretation required transponder operation and clear identification of foreign aircraft near declared exclusion zones.²³See generally Deeks, supra note 18 (specifying Russia’s argument that the U.S. was wrongfully operating without transponder use); see also Schmitt, supra note 19 (discussing Russia’s maneuvers as a violation of due regard according to UNCLOS Article 87(2)).

Similarly, in April 2001, a U.S. reconnaissance aircraft collided with a Chinese fighter jet near Hainan Island, resulting in the loss of the Chinese aircraft and pilot.²⁴EP-3 Collision, Crew Detainment, Release and Homecoming, Naval Hist. & Heritage Command (Oct. 10, 2024), https://www.history.navy.mil/research/archives/Collections/ncdu-det-206/2001/ep-3-collision–crew-detainment-and-homecoming.html (on file with American University International Law Review). The U.S. argued that China violated the due regard principle by flying underneath and dangerously close to the aircraft, instead of practicing internationally recognized interception procedures.²⁵Memorandum for Secretary of Defense Deputy Secretary of Defense, EP-3 Incident–Guidance on Legal Issues (Apr. 6, 2001) [hereinafter Memorandum on EP-3 Incident] (on file with Nat’l Security Archive). China maintained that intelligence-gathering flights within the two-hundred nautical mile radius of its EEZ posed an inherent threat to its security interests.²⁶Raul Pedrozo, Military Activities in the Exclusive Economic Zone: East Asia Focus, 90 Int’l L. Stud. 514, 527 (2014) (“Beijing responded that intelligence collection posed a threat to China’s national security interests and that U.S. military aircraft therefore only had a right of overflight in the EEZ.”). The resulting U.S.-China tensions depict the necessity for a standardized due regard procedure in light of cutting-edge aerial technology and increasing number of aircraft sharing the same airspace.²⁷See id.; Memorandum on EP-3 Incident, supra note 25 (explaining the U.S.’ stance on the EP-3 incident and China’s failure to operate with due regard); Interim Guidance Material, supra note 9, at 27 (discussing the need for standardized practices with increasing civil and state aircraft sharing the same airspace).

V. Standardizing Due Regard Obligations Under International Law

To prevent future incidents, the ICAO should standardize the operational meaning of due regard for state aircraft by providing member states with clear and enforceable requirements.²⁸See Interim Guidance Material, supra note 9, at 27 (“In light of Article 3 (d) it should be the role of ICAO to support States in harmonizing their state aircraft operations and the respective services in a regional and, ideally, a global context.”). Such requirements should include transponder usage, communication with ATC, and minimum safe distance standards when operating in or near disputed airspace.²⁹See supra Part IV (discussing the conflicting requirements for state aircraft by different countries); Due Regard, SKYbrary Aviation Safety, https://skybrary.aero/articles/due-regard (on file with American University International Law Review) (last visited Oct. 18, 2024) (listing possible approaches for state aircraft to mitigate the impact of due regard on civil aircraft).

VI. Conclusion

Escalating conflicts arising from differing interpretations of the due regard principle for state aircraft underscores the need for the ICAO to establish standardized procedures, particularly for state-authorized reconnaissance missions.³⁰See supra Part IV–V; Interim Guidance Material, supra note 9, at 27 (acknowledging the need for ICAO to ensure states harmonize state aircraft operations); Bourbonniere & Haeck, supra note 7, at 887 (discussing the importance of minimum civil-military safety regulations).   By replacing state interpretations with a uniform definition, the ICAO would ensure civil aircraft safety and establish a clear, legally binding precedent.³¹See generally Interim Guidance Material, supra note 9, at 27 (the ICAO must ensure global cooperation between state and civil aircraft); Bourbonniere & Haeck, supra note 7, at 887 (noting that air traffic safety can only be achieved by cooperation with all state using air travel as a medium).