Understanding the Use of Zones and the Concept of Proportionality: Enduring Lessons from the Falklands War

On 2 April 1982 Argentina invaded the Falkland Islands (alternatively, the Islas Malvinas). The resulting conflict lasted 74 days and claimed the lives of 255 UK military personnel and 652 Argentine servicemen. The conflict raises a myriad of legal issues but at its core is the issue of sovereignty (here). However complicated the issue, disputes over sovereignty did not legally authorise the Argentine invasion (see UNSCR). This post will not go over the vexed issue of sovereignty but will instead focus on two select issues relating to the conduct of hostilities. The Falklands War has largely receded from thought but lingering doubts over the legality of a Total Exclusion Zone (TEZ) established by the UK and its torpedoing of the Belgrano endure. By focusing on the issue of zones and the concept of proportionality this post will seek to provide clarity to two often misunderstood areas of law that are of vital importance to contemporary military operations.

The UK Total Exclusion Zone

A few days after the Argentinian invasion the UK issued a notice indicating that, from 12 April 1982, a Maritime Exclusion Zone (MEZ) would be in force, extending 200 nautical miles from the centre of the Falklands. On 28 April, the UK declared a TEZ that encompassed the same geographical area as the MEZ but was broader in scope regarding ratione personae.  In essence, the TEZ stated that any ship or aircraft entering the TEZ that was not authorised to be there by the UK Ministry of Defence was deemed to be operating in support of the occupation, regarded as hostile, and therefore liable to attack.

As the UK Manual on the Law of Armed Conflict (the UK Manual), the San Remo Manual on Armed Conflicts at Sea (the San Remo Manual) and Helsinki Principles on the Law of Maritime Neutrality all set out, the establishment of exclusion zones is permitted. However, these authorities also make clear that the same body of law applies both inside and outside the zone. That being the case, the UK would still need to do everything reasonably practicable to verify that any entrant to the TEZ was a valid military objective. It is therefore problematic that the wording of the TEZ can be read as indicating a ‘free-fire zone’ was in place. Indeed, based on Nuremberg Tribunal jurisprudence and custom, Wolff Heintschel von Heinegg has suggested that “the legality of the TEZ or of attacks therein was more than questionable”. This highlights two points that need separating: (a) the legality of any attacks that took place within the TEZ; and (b) whether the mere announcement of an exclusion zone may of itself amount to an internationally wrongful act.

Attacks within the TEZ were, crucially, only on military objectives. UK forces avoided attacking any neutral ships or aircraft. Moreover, unauthorised Argentinian merchant craft were merely compelled to leave the TEZ after being ‘circled’ or ‘buzzed’ by UK military aircraft (as acknowledged by the Permanent Representative of Argentina to the UN at the time). An Argentine fishing trawler, the Narwal, was attacked by UK forces but on the basis it was regularly engaged in reporting the location of Royal Navy warships and carried an Argentine Navy detachment. Therefore, having reviewed what targeting activity actually occurred within the TEZ, UK forces did comply with the principle of distinction.

In terms of whether the mere announcement of the TEZ was unlawful, I will assume that the use of the phrase “liable to attack” is approximate to “will be attacked” (an interpretation not supported in light of UK practice). In contrast to the jus ad bellum, LOAC does not generally prohibit threats of force and where it does these provisions are inapposite regarding the TEZ (e.g. Arts 40 and 51(2) of Additional Protocol I of 1977 (API)). Moreover, presupposing LOAC is concerned with mental harm, any threat of violence within the TEZ was not aimed at a particular individual. Accordingly, as Sivakumaran has noted, any threat is one step removed and would unlikely amount to violence to mental well-being.

Finally, it is generally recognised that exclusion zones must meet certain conditions to be valid. The UK Manual (para 13.78) and San Remo Manual (rule 106) set out the same conditions for the establishment of a permissible zone. In its Commentary the San Remo Manual indicates the TEZ met these conditions. This view is supported by W J Fenrick, based on the remote geographical location of the Falklands. That only the former USSR objected to the establishment of the TEZ is significant.

The Concept of Proportionality: Targeting the Belgrano

The Belgrano was an Argentinean cruiser carrying more than 1,000 military personnel and escorted by 2 destroyers when, located 35 miles outside the TEZ and apparently sailing away from the British fleet, it was torpedoed by HMS Conqueror. The decision to sink the Belgrano became a political issue in the UK due to the Secretary of State for Defence, John Nott, originally announcing the Belgrano was “closing on elements of our task force”. Focusing instead on the legal issue, analysis of the decision to target the Belgrano often centres on ‘proportionality’. From the outset it is, therefore, important to distinguish between three different conceptions of proportionality applicable to warfare.

First, it is universally accepted that a State’s right to use force in self-defence is limited to acts that are necessary and proportionate to the threat faced. This is the jus ad bellum requirement of proportionality. Second, LOAC stipulates that an attack against a military objective may not proceed if it is expected to cause incidental loss of civilian life or damage to civilian property which would be excessive in relation to the concrete and direct military advantage anticipated. This is the rule of proportionality under the jus in bello. Third, the dominant intellectual tradition of thought on the morality of war (i.e. the Just War Tradition) includes the criterion of proportionality when looking at both ‘just recourse’ and ‘just conduct’. As the Department of Defense Law of War Manual highlights, the Just War Tradition provides part of the philosophical foundation for LOAC. However, this article will focus on the sinking of the Belgrano as judged against the jus ad bellum and jus in bello.

Proportionality in LOAC 

The rule of proportionality is codified in Articles 51(5)(b), 57(2)(a)(iii) and 57(2)(b) of API.  As Aurel Sari and I argue in greater detail in a forthcoming publication, the protective scope of this rule is strictly confined to civilians. This means there was no violation of the jus in bello rule of proportionality in the targeting of the Belgrano. That rule simply does not apply to attacks that only effect combatants or military objects. Ryan Goodman has suggested that the principle of “least-restrictive-means” demands that a belligerent must employ only such degree of violence against enemy combatants as is necessary and proportionate to accomplishing a military objective (here). If correct this would require an assessment of the proportionality of the harm that befell the sailors on board the Belgrano. Goodman’s argument has been criticised elsewhere (here and here). For our purposes it is sufficient to maintain that Goodman’s argument, with all that it entails for conducting military operations, finds no support in State practice.

Jus ad Bellum and Proportionality

The Belgrano was targeted a month after the Falklands had been forcibly invaded. It is incontrovertible that an international armed conflict was in existence and that the UK was exercising its inherent right of self-defence. Indeed, the UK’s actions in recovering the Falklands shows such a right is not placed in abeyance merely because the Security Council has passed a resolution calling for one of the parties to the conflict to withdraw. Some commentators argue that once an armed conflict exists the only question to be asked under the jus ad bellum is who started the conflict (here). In other words, proportionality is irrelevant once hostilities are under way. Most commentators appear to disagree with this view (e.g. here, here and here) and, significantly, this is at odds with the position in the UK Manual (para 2.8). It is relevant, therefore, to ask whether the torpedoing of the Belgrano was a proportionate act under the jus ad bellum.

Proportionality allows an injured State to do what is reasonably necessary to deal with the threat it is facing. In terms of the threat facing the British fleet, UK signals intelligence intercepted a communication prior to the torpedoing of the Belgrano that confirmed it was to rendezvous with other vessels back inside the TEZ in order to engage in a pincer attack (here). Moreover, far from retreating from the Royal Navy, the Captain of the Belgrano confirmed any change of direction was a temporary manoeuvre and that he had been commanded to attack the British fleet wherever he encountered it (here and here). The threat posed by the Belgrano meant its targeting was necessary and proportionate despite it being positioned just outside the TEZ. To say otherwise would see the jus ad bellum imbued with a quixotic understanding that is at odds with military realities.

Enduring Legal Lessons

It is paramount that an otherwise protected vessel or aircraft does not lose protection by merely crossing an imaginary line drawn in the ocean or adjacent airspace. This lesson is as relevant to defensive zones in times of heightened tension as exclusion zones during conflict. In contemporary practice, Air Defence Identification Zones (ADIZs) are frequently employed by States. An ADIZ is, essentially, non-territorial airspace unilaterally designated for the purpose of aircraft identification. In 2013, China unilaterally established an ADIZ over the East China Sea (here). China’s establishment of an ADIZ in international airspace is not of itself illegal. However, the manner in which Beijing made its announcement is problematic: “China’s armed forces will adopt defensive emergency measures to respond to aircraft that do not cooperate in the identification or refuse to follow the instructions.” China has not explained what these measures might involve but, crucially, has not executed any measures to date (here). Parallels can therefore be drawn with the TEZ in that the practical implementation of the declared zone has not given rise to an unlawful use of force. This explains why debate over the ADIZ has focused on the legality of specific characteristics of the zone (here, here and here).

China has threatened to declare an ADIZ over disputed territory in the South China Sea following the PCA decision there is no legal basis for China’s ‘nine-dash line’. In such circumstances,  a clear understanding of what zones allow and do not allow regarding enforcement measures remains vital. As asserted in the Memorial submitted by the UK to the ICJ in proceedings concerning the Aerial Incident of 27 July 1955 (United Kingdom v. Bulgaria), “the use of armed force against foreign ships or aircraft is not justified in international law unless it is used in the legitimate exercise of the right of self-defence”. To be legitimate any such force would need to be both necessary and proportionate.

As has been demonstrated, the concept of proportionality is a fundamental limitation of the use of force in both the jus as bellum and jus in bello. A proper understanding of its requirements is also crucial in light of a trend of misapplying the concept when formulating accusations of illegality regarding military operations. For example, in 2012 then Argentinian president Cristina Fernández de Kirchner claimed the decision to sink the Belgrano was a “war crime” (here). Having set out what the concept of proportionality encompasses, this claim does not withstand scrutiny.

The author is a serving member of the Royal Air Force Legal Branch. The views expressed in this article are those of the author alone and not those of the RAF, the UK Ministry of Defence or the UK Government.