1.1 R egulating A rmed S warms U nder I nternational L aw
By Michael J. Pollard (University of the West of England)
Introduction A variety of emerging weapons technologies such as hypersonic missiles, 8 loyal wingman systems, 9 electromagnetic pulse (EMP) weapons, 10 and laser weapons 11 have the potential to revolutionise military affairs. 12 Despite the military advantages these weapons offer however, they do not represent a significant challenge in terms of their compliance with international law when deployed in armed conflict. Instead, the military decision-maker responsible for authorising their deployment (present and/or future) will remain governed by the obligations contained within IHL, not least the principle of distinction. 13 Of the known military systems currently under development, 14 however, perhaps the most controversial is Autunomous Weapons Systems (AWS). 15 Indeed, due, inter 8 There is no strict definition of what constitutes a hypersonic missile, but it should be capable of travelling at speeds in excess of 3500mph. See e.g., Boyd I, ‘How hypersonic missiles work and the unique threats they pose – an aerospace engineer explains’ ( The Conversation , 15 April 2022) accessed 7 November 2023. 9 See e.g., Boeing, ‘Loyal Wingman: Uncrewed but not alone’ ( Boeing , 23 November 2023) accessed 1 November 2023. 10 See, e.g., Mizokami K, ‘The Army’s New Drone Killer Can Fry Whole Swarms in Midair’ ( Popular mechanics , 7 November 2023) accessed 14 December 2023. 11 See e.g., Judson J, ‘US Army awards Boeing, General Atomics contract to develop powerful laser weapon’ ( Defence News , 3 November 2021) accessed 21 October 2023. 12 Revolution in military Affairs (RMA) is a term that is applied to a new technology that significantly changes the way war is fought. For example, the aircraft carrier, allowed nations to move their tactical and operational aircraft much closer to a battlefield, and more quickly than had previously been possible. 13 Distinction, or the basic rule, is codified in Art. 48 Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), 8 June 1977, 1125 UNTS 3 (hereinafter API). Art. 48 provides, ‘In order to ensure respect for and protection of the civilian population and civilian objects, the Parties to the conflict shall at all times distinguish between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objectives’. This principle is also considered to be customary in nature, see e.g., International Committee of the Red Cross (hereinafter ICRC), Customary International Law database, Rule 1, available at, accessed 31 October 2023. 14 Noting that military technology is, for reasons that require little explanation, typically shrouded in secrecy. 15 From what started as relatively niche discussion in 2007 (see generally e.g., Sparrow R, ‘Killer Robots’ (2007) 24(1) Journal of Applied Philosophy 62; (Speaker T, O’Donnell S, Wittemyer G et al, ‘A Global Community-Sourced Assessment of the State of Conservation Technology’ (2022) 36(3) Conserv Biol 13871), there is now a wealth of discussion.
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