DISPUTED IMBLs AND ADIZs - IMPLICATIONS FOR MARITIME AIR OPERATIONS

The waters of the world form one vast expanse. While land may be enveloped by the sea - and the Continents are so enveloped - the Oceans are divided only by artificial boundaries.¹

The above quote highlights the distinguishing characteristic of ‘world’s oldest global commons’ that is often used to symbolise the maritime domain. While these words stated so eloquently by an eminent Indian historian-diplomat, also considered a doyen of Indian maritime strategic thinking, do allude to the inclusive nature of oceanic domain, they also highlight the relatively permissible nature of legal order that prevails at sea which is quite different from that on land.

The 1982 United Nation Convention on the Laws of the Sea (UNCLOS), also referred to as the “A Constitution for the Oceans” accords a gradually receding jurisdictional regime as one moves seawards away from land.² A fundamental distinctive feature of this legal regime is that except in some very special and extraordinary circumstances, a coastal state does not enjoy ‘absolute immutable sovereignty’ on any portion of its adjacent seas. To explain, while land borders in the first instance are ‘delineated on maps’ and then ‘demarcated on ground’; whereas at sea - in case of an overlap between the maritime entitlements of adjacent or opposing coastal states, the division is determined through the process known as ‘delimitation’. This phrase ‘delimitation’ itself signifies that it is only the ’limits’ of rights, duties, responsibilities and obligations of the involved coastal states that are being decided. It may be interesting to note that even on nautical charts, while the international land boundaries are marked, but only the furthest limits of maritime delimitation of a costal state in a very few cases, which have been formalised through a treaty/agreement are marked. The individual maritime entitlements, that are, the Territorial Seas (TS), Exclusive Economic Zone (EEZ) and the Continental Shelf (CS) are not depicted. Even the relevant points for determining the baseline of a coastal state are not shown. It is also important to reiterate that an important facet of maritime military operations is that the belligerent actions cannot detract from the legitimate use of the seas by neutral ships and aircraft including those of military character.³

With this introduction, the article seeks to analyse the implications on maritime air operations when disputes exist on the alignment of International Maritime Boundary Line (IMBL) with an adjacent or opposing coastal state, and; whilst operating in airspace that falls under the ambit of two or more Air Defence Identification Zones (ADIZs) as well as those ADIZs with restrictive operating conditions. The paper uses the extant legal and scholarly discourse as the points of departure and reference, as these would determine the range of a priori actionable options that would be available to any Op Commander, planning staff and Commander at Sea. While it is not so important to be aware of exact legal nuances, a fair understanding of guiding precepts always helps in devising smart options as well as making optimal choices under conditions of uncertainty, which are inherent in complex military operations.

Since the two main issues, namely, IMBL and ADIZ involve quite different conceptual considerations, as well as the scope and content of associated issues, these have been discussed separately in the paper.

Broad Overview - Delineation of Maritime Entitlements and Airspace

At this stage, it is useful to broadly deconstruct the maritime entitlements of a coastal state on its adjacent ocean space and the adjoining airspace in accordance with the UNCLOS and other relevant international law provisions.

Maritime Entitlements. Maritime entitlements accruing from UNCLOS can be broadly divided into two categories, namely, those of ‘sovereignty’ and ‘sovereign rights’ contextualisation, as discussed in the following paragraphs.

Sovereignty. Under this category, there exist two further sub-divisions as follows: -

Historic Bay/Title. The first is of ‘absolute immutable sovereignty’ which would obtain in case of a historic title or historic bay.⁴ In such cases, the sea space so claimed by a coastal state is treated in exactly the same manner as a land territory or, in maritime terms, as internal waters.⁵ The domestic law of the land of the coastal states applies in toto and in its entirety. India has claimed parts of Palk Bay and Gulf of Mannar as negotiated during the agreements with Sri Lanka in 1974 and 1976 (Fig 1). The official proclamation to this effect was first made through Gazette Notification in 1977 and once again reiterated while promulgating the baseline system and the relevant coordinates in May 2009.⁶

Territorial Seas (TS). The second sub-category of maritime space with sovereignty connotations is that of Territorial Seas with a maximum breadth of 12 nautical miles.⁷ Within this breadth of maritime space, the law of the land also applies virtually in toto but with one sole exception of the right of innocent passage which specifies “…ships of all States, whether coastal or land-locked, enjoy the right of innocent passage through the territorial sea.”⁸ It would thus be apparent that a coastal state enjoys general sovereignty as opposed to immutable absolute sovereignty in the case of a land territory, internal waters or historic waters/bays.

Fig 1: Historic Waters Claim in Palk Bay & Gulf of Mannar (Shaded in Grey, Not to Scale, for representative purpose only) Source: National Archives, New Delhi; Author’s Depiction

Sovereign Rights. The second category of maritime spaces are those of ‘sovereign rights’ context and these include the Exclusive Economic Zone (EEZ) and Continental Shelf (CS) wherein the coastal state has sole exclusive access to resources contained in these zones. In the EEZ, the coastal state enjoys rights to resources contained in the ‘suprajacent’ waters, that is, above and within the water columns as well as on and below the sea bed.⁹ As far as the Continental Shelf entitlement is concerned, it can extend up to a maximum distance of 350 nautical miles as measured from the baseline, subject to certain qualifying and geographical constraints. In this instance, however, the sovereign rights to resources are limited to these on and below the sea bed.¹⁰ The distinction in this sub-category to be understood is that the rights of a coastal state are strictly limited to resource exploitation in a sustainable manner and their conservation. Contiguous Zone has not been included in the discussions as it is more of an enforcement zone and not considered as a maritime entitlement in true sense of the term.

High Seas Freedoms and their Applicability

High Seas are defined as those lying beyond the limits of EEZ and the following high seas freedoms are available to ships and aircraft of all nations: - ¹¹

• Freedom of navigation

• Freedom of overflight

• Freedom to lay submarine cables and pipelines, subject to Part VI of UNCLOS

• Freedom to construct artificial islands and other installations permitted under international law, subject to Part VI of UNCLOS

• Freedom of fishing, subject to the conditions laid down in section 2

• Freedom of scientific research, subject to Parts VI and XIII of UNCLOS

However, a more nuanced reading of the above provision in conjunction with other relevant articles of the UNCLOS bring out that the High Seas Freedoms of Navigation and Overflight as mentioned above, in practical terms, commences beyond the TS limits of a coastal state.¹²

Delineation of National/International Airspaces and Status of Military Aircraft.

The delineation of national and airspace was specified in the 1944 Chicago Convention on International Civil Aviation and has been retained in toto within the much expanded Ninth Edition of International Civil Aviation Organisation (ICAO) document titled “Convention on International Civil Aviation”, also frequently referred to it by the technical designation, Doc 7300.¹³ The national airspace is defined as that extending over the territory of a State as follows-

“For the purposes of this Convention the territory of a State shall be deemed to be the land areas and territorial waters thereto under the sovereignty, suzerainty, protection or mandate of such State.” ¹⁴

The provisions of this Convention apply only to civil aircraft. State aircraft, which include military aircraft, are exempt, except that the operations of State aircraft are to be undertaken with due regard to the safety of navigation of civil aircraft.¹⁵ In addition, it is also specified that “….no state aircraft of a contracting State shall fly over the territory of another State or land thereon without authorization…” which means that the exempt status of State Aircraft only applies within the respective national airspace and the international airspace.¹⁶ Therefore, unlike ships including warships and submarines on surface, there is no regime of innocent passage for aircraft within the TS of a coastal state. In fact, launch and recovery of an aircraft within the TS limits of a coastal state is a non-innocent activity jeopardising its peace, good order or security.¹⁷

Disputed IMBLs

The term IMBL is a characteristic and inexact as well as problematic terminology which finds mention only in India Navy’s lexicon and may have contributed to its increasing usage among the national scholarly community. In all humility, it is somewhat disconcerting to note that the term IMBL is also used in the Indo-Pak context while discussing operations in Sir Creek and adjoining areas when the land boundary itself within the creek and the consequential maritime delimitation remain disputed. To add, this exact term, IMBL, has not been used even once in the 12 delimitation agreements with maritime neighbours which were concluded between Jul 1974 to Oct 93.¹⁸ However, in all these delimitation agreements, the term ‘maritime boundary’ finds repeated mention while formalising delimitation of not only the TS but also the EEZ and CS limits with respective countries.

The use of terms ‘IMBL’ as also ‘maritime boundary’ are also quite problematic as these are emblematic of a terrestrial mind-set and an inadequate understanding of maritime domain by the entities involved in framing of these treaty texts since there are no boundaries at sea but only limits of jurisdiction which are never ever absolute except in very rare circumstances, as discussed in the paper.

For the purpose of this paper, ‘disputed IMBL’ has been construed as circumstances wherein an overlap exists between the limits (spatial extent) of maritime entitlements claimed by two or more coastal states.

 In so far as the question of a disputed IMBL, or as mentioned earlier, the circumstances wherein an overlap exists between the limits (spatial extent) of maritime entitlements claimed by two or more coastal states is concerned, a hypothetical case encompassing all possible circumstances has been generated between Coastal States A and B. These two states are geographically adjacent with no dispute over the land border including its Land Boundary Terminal (LBT), Point P, in Figure 2, which is the last point on the coast. Both these states also agree that the adjoining gulf is a historic bay. The geological conditions are also favourable for claiming Extended Continental Shelf entitlement up to 350 nautical miles . However, they disagree on the alignment ofmaritime delimitation line. Coastal Sate A claims that the delimitation line should run in a due East-to-West direction, whereas Coastal State B claims that the delimitation line should be extended along the alignment of land border. For a detailed depiction of aforementioned issues, see Fig 2.

This difference in claim positions about the alignment of maritime delimitation would generate seaward zones of overlap as follows: -

Taking into consideration the twin criteria of the High Seas Freedom of Navigation and Overflight as well as the delineation of national and international airspace, both extending from the breadth of territorial seas, the question of maritime air operations in case of disputed IMBLs or an overlap among maritime entitlements of coastal states is actually relevant up to these spatial limits only. As brought out above, the overlap area bound by the contending maritime delimitations lines of Coastal States A & B bound by the triangle PQR and the polygon QRST at Figure 2 above would be of relevance for planning and conduct of maritime air operations. The dispute in terms of maritime delimitation beyond the limits of territorial seas, that is, sovereign resource rights for overlapping EEZ bound by the polygon STUV and for Continental Shelf by the polygon UVWX are in fact inconsequential for discussion here as these zones are situated in international airspace and aircraft of all states would enjoy the High Seas Freedom of Overflight.

Within the overlap area with sovereignty considerations, it is the general practice of states to avoid aircraft operations unless escalation is permitted or sought. This is borne out by empirical international state practice and has no particular or specified norm of international behaviour that supports this proposition. It is surmised that such conduct emanates from the perception among most nation states to avoid heightened tensions as use of airpower is perceived to be escalatory. In practice, nation states, in almost all cases, resort to the use of surface vessels, both civilian and military in character, to assert their claim position, as evidenced in the recent repeated stand-offs in the East and South China Seas.

There is, however, some recent albeit isolated evidence of states resorting to military aircraft operations in areas of disputed sovereignty to assert their positions. A noteworthy example is the use of sea based naval airpower by the United Sates Navy to assert its opposition to the historic claim position of Libya regarding Gulf of Sirte in Northern Mediterranean commencing 1973. The simmering tensions over the issue resulted in shooting down of two Libyan MiGs in Aug 1989.¹⁹

Disputed ADIZ

To arrive at an understanding of air operations in a disputed ADIZ, there is a need to expand upon the legal or implicit functional premise that undergird this concept. ADIZ has been defined as: -

ADIZ is airspace over land or water in which the identification, location and control of civil aircraft is undertaken in the interest of national security. This may extend beyond a country’s territory to give a country more time to respond to a possible hostile aircraft.²⁰

Airspace of defined dimensions within which the ready identification, location, and control of airborne vehicles are required.²¹

Air Defence Identification Zone (ADIZ) means an area of airspace over land or water in which the ready identification, location, and control of all aircraft (except for Department of Defense and law enforcement aircraft) is required in the interest of national security.²²

There is no persuasive evidence either from a legal standpoint or from scholarly material which supports the concept of an ADIZ. However, ADIZs have been established by a large number of countries. Some scholars have argued that nation states have certain claims to secure their sovereign rights which include national security. These can be exercised in support of such a purpose as long as it is not inconsistent with International Law.²³ In this regard, the closest possible legal justification for establishing ADIZ, although indirectly stated, is Article 3 of Chicago Convention/Doc 7300 which is reproduced below in complete detail with important text in bold typeface and italics for highlighting the critical provisions: -²⁴

• The contracting States recognize that every State must refrain from resorting to the use of weapons against civil aircraft in flight and that, in case of interception, the lives of persons on board and the safety of aircraft must not be endangered. This provision shall not be interpreted as modifying in any way the rights and obligations of States set forth in the Charter of the United Nations (which includes the inherent right of self-defence i.a.w. Art 51).

• The contracting States recognize that every State, in the exercise of its sovereignty, is entitled to require the landing at some designated airport of a civil aircraft flying above its territory without authority or if there are reasonable grounds to conclude that it is being used for any purpose inconsistent with the aims of this Convention; it may also give such violations. For this purpose, the contracting States may resort to any appropriate means consistent with relevant rules of international law, including the relevant provisions of this Convention, specifically paragraph (a) of this Article. Each contracting State agrees to publish its regulations in force regarding the interception of civil aircraft.

• Every civil aircraft shall comply with an order given in conformity with paragraph (b) of this Article. To this end each contracting State shall establish all necessary provisions in its national laws or regulations to make such compliance mandatory for any civil aircraft registered in that State or operated by an operator who has his principal place of business or permanent residence in that State. Each contracting State shall make any violation of such applicable laws or regulations punishable by severe penalties and shall submit the case to its competent authorities in accordance with its laws or regulations.

• Each contracting State shall take appropriate measures to prohibit the deliberate use of any civil aircraft registered in that State or operated by an operator who has his principal place of business or permanent residence in that State for any purpose inconsistent with the aims of this Convention. This provision shall not affect paragraph (a) or derogate from paragraphs (b) and (c) of this Article.

The above cited provisions clearly bring out that while the concept of an ADIZ is not implicitly codified, but it is not prohibited either. At this stage, it is useful to highlight that ADIZ is not a force fire zone but merely an aid in support of national air defence and to prevent unlawful use of national airspace.

The support for an ADIZ from a very small section of law scholars comes from precautionary principle where a state is authorised to take appropriate measures to prevent transboundary harm and goes on to emphasise that the absence of empirical or scientific evidence in no way impairs the states from taking suitable action to prevent a potential or anticipated harm before its actual manifestation.²⁵ While this principle is finding ever greater resonance among the comity of nations especially while dealing with transboundary environmental implications; the legal premise of this proposition is considered tenuous and fragile both in scope as well as content.

Yet another section of academics has forwarded the doctrines of anticipatory self-defence, preventive self-defence and pre-emption in support of ADIZ.²⁶ However, these doctrines by their nature and criteria for initiation are more suitable for a case of an ADIZ violation where threat or use of force becomes necessary and not in normal circumstances. While the doctrine of anticipatory self-defence is enshrined in customary international law, the other two legal precepts of pre-emption and preventive self-defence remain controversial subjects of great debate and low universal acceptance.

Be that as it may, promulgation of an ADIZ extending up to the limits of national airspace, that is, up to the limits of territorial sea of a coastal state cannot be argued against. ADIZ extending into international airspace, however, are implicit with differing nuances. Generally speaking, as a norm, the measures instituted for such ADIZ are applicable to civil aircraft but are increasingly being enforced for military aircraft as well. As brought out earlier, state aircraft which include those of military character are not exempt from national civil aviation procedures in another states’ national airspace. However, more often than not, compliance with ADIZ norms is expected when an aircraft is expected to enter or transit through the national airspace. Most academics agree that an aircraft transiting through the ADIZ but not expected to enter/transit through the national airspace is not required to comply with ADIZ provisions. The salient aspects of these discussions are highlighted at Fig 3. Certain countries like Canada in the North Atlantic and the Chinese ADIZ in East China Sea, however require even aircraft transiting through the ADIZ to comply with the laid down provisions.

The Chinese ADIZ in East China Sea is also unique on two counts; firstly, it overlaps the Japanese ADIZ and in a small measure the South Korean ADIZ. Secondly, even military aircraft are expected to comply with ADIZ provisions irrespective of whether they are expected to enter or transit through the Chinese national airspace.

ADIZ provisions which require even transiting aircraft to comply with the provisions and those mandating adherence by military aircraft while operating in international airspace are considered excessive by most scholars. In such cases, the general recommended practice is to assert the exempt status of ‘State Aircraft’ as laid down in Chicago Convention/Doc 7300. Whether an overlap exists in spatial extent of ADIZs is of no operational consequence while undertaking maritime military operations due to exempt status of military aircraft.

In practice, however, most states have issued advisories to their civil aircraft to comply with ADIZ provisions even if they are excessive like in the case of East China Sea ADIZ by China. Assertions of differing national positions is articulated through policy announcements and demonstrated by military aircraft operations.

Fig 3: ADIZ Compliance (Representative Depiction, not to scale) Source: Author’s Compilation

Conclusion

Maritime air operations in disputed zones with overlapping sovereignty connotations is generally neither practiced and nor is the recommended norm during normal circumstances. However, such operations, deliberately planned are feasible during states of heightened tensions and full-fledged hostilities.

Military aircraft must abide by ADIZ provisions while entering or transiting through the national airspace of a coastal state. However, compliance with excessive provisions while operating beyond the limits of national airspace is not recommended. In such cases, the exempt status must be asserted in full measure.

The following quote brings out articulated more than 100 years ago by a British senior officer captures the essence and importance of international law in current milieu characterised by instant and distributed communications as also pervasive media presence: -

The strategist may have to reckon with the international jurist as well as with the enemy.²⁷ 

Endnotes

1. KM Panikkar, India and the Indian Ocean: An Essay on the Influence of Sea Power on Indian History (London: George Allen & Unwin, 1951), 18.

2. Tommy Koh “A Constitution for the Oceans,” Remarks by Tommy T.B. Koh of Singapore, President of the Third United Nations Conference on the Law of the Sea, Montego Bay, Jamaica, 11 December 1982. https://www.un.org/depts/los/convention_agreements/texts/koh_english.pdf, accessed 16 February 2022.

3. International Institute of Humanitarian Law, “San Remo Manual on International Law Applicable to Armed Conflicts at Sea,” San Remo, 1994, Para 12 which states “…carrying out operations in areas where neutral States enjoy sovereign rights, jurisdiction, or other rights under general international law, belligerents shall have due regard for the legitimate rights and duties of those neutral States.”

4. United Nations, Department of Ocean Affairs and Law of the Sea, “United Nations Convention on the Law of the Sea (UNCLOS),” See Article 10 Para 6 for Historic Bays and Article 15 for Historic Titles. https://www.un.org/depts/los/convention_agreements/texts/unclos/unclos_e.pdf, accessed 12 February 2022.

5. For detailed discussion including the essential prerequisites for claiming historic rights at sea, See United Nations, International Law Commission, “Juridical Regime of Historic Waters including Historic Bays,”https://legal.un.org/ilc/documentation/english/a_cn4_143.pdf, accessed 10 February 2022. The three main criteria for historic claims at sea are – formal proclamation of claim position; continuous exercise of claim, and; general toleration by international community. For a detailed examination of the relevance or otherwise of the historic rights sea, see, Symmons, Clive R. Historic Waters in the Law of the Sea: A Modern Re-Appraisal. Leiden: Brill Nijhoff, 2019.

6. Government of India, Gazette of India, Extraordinary, Ministry of External Affairs, G.S.R.17(E) dated 15 January 1977 and Government of India, Gazette of India, Extraordinary, Ministry of External Affairs, S.O. 1197(E) dated 11 May 2009.

7. UNCLOS, Note 5, Articles 2 & 3.

8. Ibid., Articles 17-19.

9. Op Cit., n.7, Articles 55-59.

10. Op Cit., n.7, Articles 76-78 and 83.

11. Op Cit., n.7, Articles 86.

12. Op Cit., n.7, Article 86 to be read in conjunction with Articles 55-58, 76-78 and 87-90.

13. International Civil Aviation Organization, “Convention on International Civil Aviation.” https://www.icao.int/publications/Documents/7300_cons.pdf, accessed 14 February 2022.

14. Ibid., Article 2.

15. Op Cit., n.13, Article 3(d).

16. Op Cit., n.13, Article 3(c).

17. UNCLOS, Op Cit., n.7, Article 19.

18. Government of India, Ministry of External Affairs website by the path Media Centre>Other Documents>Indian Treaties Database and using an appropriate search string thereafter.

19. Joseph Stanik, El Dorado Canyon - Reagan's Undeclared War with Qaddafi (Annapolis: Naval Institute Press, 2016).

20. Headquarters Integrated Defence Staff, “Joint Services Glossary of Military Terms,” 2019, 32.

21. United States Department of Defence, “DOD Dictionary of Military and Associated Terms,” November 2021. https://www.jcs.mil/Portals/36/Documents/Doctrine/pubs/dictionary.pdf, accessed 20 February 2022.

22. United States Federal Aviation Authority, “Federal Aviation Administration Regulations, 14 CFR § 99.3,” ECFR. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-99/subpart-A/section-99.3, accessed 21 February 2022.

23. Myres S. McDougal, Harold D. Lasswell and Ivan A. Vlasic, Law and Public Order in Spaceb(New Haven: Yale University Press, 1963), 305-310.

24. This amendment was incorporated in the Convention at the 25th (Extraordinary) Session of the Assembly on 10 May 1984 by adopting the Protocol introducing Article 3bis. This amendment came into force on 01 October 1998.

25. ICAO, Convention, Note 15, Indirect and Implicitly Reference Contained in the Text of Article 2.

26. For Doctrine of Anticipatory Self-Defence, see SS Carolines case. For preventive and pre-emptive self-defence, see writings on the subject of Bush Doctrine especially his address to West Point on 01 June 2002 and US National Security Strategy of September 2002.

27. Cyprian Bridge, The Art of Naval Warfare: Introductory Observations (London: Smith, Elder, 1907), 162.