Half a league, half a league,
Half a league onward,
All in the valley of Death
Rode the six hundred none.
In his narrative poem, ‘The Charge of the Light Brigade’, Tennyson recounts the tragedy of war. Disguised under the mask of celebration, whilst honouring the relentless sacrifice of soldiers engaged in combat and painting them with strokes of heroism and selflessness, Tennyson hints at the disturbing horrors of war – death. But what of a war without the risk of death?
Since 9/11, the USA has deployed unmanned air vehicles (UAVs), also known as drones, as part of their counterterrorism operations and national security policy against Al-Qaeda and associated groups. The use of such weapons allows states such as the USA to engage in an armed conflict without risking the lives of their soldiers. Remotely controlled, precise, and accurate, drones convey a sense of excellence: the perfect tool to attack lawful military targets whilst ensuring the safety of civilians and soldiers alike. An international humanitarian law (IHL) accomplishment.
Nonetheless, whilst intuitively appealing, the use of drones as weapons raises several issues in the context of IHL; most pertinently, with respect to the principle their usage claims conformity with: the principle of distinction. This article will focus on the paradox surrounding the principle of distinction. It will demonstrate how despite an outward compliance with the principle, the evolution of the interpretation of this principle demonstrates that the principle is not satisfied in practice, and such interpretations have a counterproductive effect leading to the proliferation of drone usage.
The structure of this article is as follows: first, it will elucidate the IHL legal framework concerning the use of drones. Then, it will explain the connection between drones and the principle of distinction. Next, it will examine how drones are deployed in practice, focusing specifically on their use by the USA to combat terrorism. In doing so, it will clarify why using weapons such as drones is often interpreted as adhering to the principle of distinction and why such interpretations are flawed. Finally, the article will conclude with the consequences of these interpretations in proliferating the usage of drones.
The legal framework: the principle of distinction
The conduct of states and non-state actors in an armed conflict is regulated by international humanitarian law (IHL), also known as the law of armed conflict (LOAC) or jus in bello. IHL seeks to balance military necessity and humanitarian concerns through its rules and principles. Underlying this body of law are four core principles: the principle of necessity, the principle of proportionality, the principle of distinction, and the principle of humanity. All four principles are found in Additional Protocol I (API) to the Geneva Conventions. The International Court of Justice (ICJ) highlighted the importance of these principles when stating that the principle of distinction and the principle of humanity are the ‘cardinal principles’ of IHL. The principle of distinction is also found in Additional Protocol II (APII) to the Geneva Conventions, which confirms that the principle is applicable in both international and non-international armed conflicts.
However, unlike the Geneva Conventions, the Additional Protocols are not ratified by all states. More pertinently, in the context of this article, states that avail drones such as the USA and Israel, as well as states upon whose territory drone strikes are carried out, such as Pakistan, are not parties to API or APII. Although both Pakistan and the USA are signatories to API and APII, they have not ratified the treaties. Nonetheless, it is widely accepted that the above four principles have obtained the status of customary international law (CIL), and are thus binding on all states engaged in an armed conflict, regardless of whether the states are parties to the APs. This has also been confirmed by the ICJ who stated, with respect to the principle of distinction and principle of humanity in particular, that these principles ‘constitute intransgressible principles of international customary law.’
Turning then, to the principle of distinction itself: the principle requires that parties to an armed conflict must differentiate between civilians and combatants, and civilian objects and military objectives. Whilst combatants and military objectives may be deliberately, lawfully, targeted by parties involved in an armed conflict; civilians and civilian objects may never be deliberately targeted. Indiscriminate attacks (attacks that do not differentiate between the aforementioned) are strictly prohibited. The aim of the principle is to ensure the immunity of civilians and civilian objects from targeting. Notwithstanding, civilians taking direct part in hostilities may also be lawfully targeted.
This article is specifically concerned with the distinction between combatants and civilians (as opposed to the distinction between military objectives and civilian objects). Combatants are defined as members of the armed forces of a party to an armed conflict who are subject to an internal disciplinary system that enforces the laws of war. In contrast, civilians are defined negatively as non-combatants, and API explicitly states that in the presence of a doubt concerning the status of an individual, such an individual is to be deemed a civilian.
Thus, embodied within the principle of distinction is an obligation that combatants must take active steps to distinguish themselves from the civilian population so that the enemy does not confuse a civilian with a combatant, and vice versa. This obligation may be carried out in several ways and is typically enforced through the requirement of armed forces wearing uniforms or displaying distinctive emblems that are visible from a distance.
The nexus between drones and the principle of distinction
Unmanned air vehicles (UAVs), also known as drones, are weapons used by parties to an armed conflict to target combatants. They are controlled remotely by human pilots. Drones are praised for their apparent IHL compliance, particularly with the principle of distinction, as proponents of drone usage argue that such weapons cause fewer civilian casualties and collateral damage in comparison to other weapons due to their accuracy and precision when targeting combatants. It is also argued that the use of these weapons allows parties to an armed conflict to lower the risk of death for their armed forces, as there are less feet on the ground. Other arguments in favour drones concern their effectiveness, both financially and as a matter of policy and national security.
This article is concerned with the first perceived advantage of drones. That is, that such weapons enable greater compliance with the principle of distinction. This argument is flawed on at least two grounds. First, the premise of the argument – that is, that drone attacks are accurate and precise – is vague. Proponents of this argument fail to differentiate between the precision of the weapon itself vs the precision of the process used to weaponise the drone. The lack of government oversight concerning the process used to weaponise the drone, and in fact, in some cases, the absence of a process in the first place, undermines the obligation centred in the principle of distinction holding that parties to an armed conflict must distinguish between civilians and combatants. Second, there is a lack of evidence supporting the contention that drones do indeed cause fewer civilian casualties in comparison to other weapons. A culmination of these two misconceived impressions has resulted in a significant lowering of the threshold to use drones, which has a paradoxical IHL effect of increasing their usage. Before assessing each of these issues, it is useful to highlight how drones operate in practice.
The usage of drones in the Pakistani context
Since 9/11, the USA is engaged in an armed conflict with “Al-Qaeda, the Taliban, and associated forces.” These groups are situated both in Afghanistan as well as in the Afghanistan-Pakistan border regions. As part of its counterterrorism operations against these groups, alongside the (now retrieved) presence of armed forces on the ground in Afghanistan, the USA has increasingly deployed drones to target the enemy. These drones are remotely controlled from areas outside the region such as Somalia, Yemen, and Pakistan.
Drones are used by states such as the USA in two ways. On the one hand, they are used for surveillance purposes to gather intelligence. Due to their ability to hover over individuals for increasingly long periods of time – anywhere between twenty and thirty hours – such weapons allow states to accurately identify targets and establish patterns of movement. Through the mid-2000s, drones were almost exclusively used for this purpose by the USA in relation to Al-Qaeda and the associated groups. On the other hand, drones also possess the capability to carry small armed weapons which allow the human pilots controlling the drones to carry out attacks. Coupled together, it is argued that these two advantages of drones allow states that utilise such weapons to adhere to the principle of distinction, as the ‘real-time’ surveillance and ‘greater command control over firing decisions’ enables states to distinguish between a combatant and civilian before attacking, which has the corollary effect of reducing civilian damage that may otherwise occur through the use of other weapons such as armed aircrafts.
Compliance with the principle of distinction or simply an illusion?
As stated above, proponents of drone strikes argue that such weapons comply with the principle of distinction because such weapons accurately distinguish between combatants and civilians. In the Nuclear Weapons Advisory Opinion, the ICJ held ‘weapons that are incapable of distinguishing between civilian and military targets’ are forbidden, but the court did not rule whether nuclear weapons are incapable of distinction. However, as the Alston Report states, ‘[t]he precision, accuracy and legality of a drone strike depend on the human intelligence upon which the targeting decision is based.’ It is submitted that this process requiring human intelligence proves to be a difficulty for the principle of distinction, as it follows that the intelligence must be accurate and capable of distinguishing between combatants and civilians. In addition, the level of training of the human pilots is also paramount in ensuring that the right target is hit. In practice, such intelligence and practice of operators does not always result in the anticipated outcome.
Turning to the USA, the strategy employed by the USA to gather intelligence is not clear as such information is classified, and many drone strikes are carried out under covert operations. However, there are reports suggesting that the USA’s strategy consists of both utilising drones and on-the-ground informants. The method of drone usage may be divided into two distinct approaches: ‘personality strikes’ and ‘signature strikes.’ The former, implemented since 2004 under the Bush administration, are strikes that the USA has a ‘high degree of confidence’ that it knows the precise identity of the target. However, from 2008 onwards, the USA has also carried out ‘signature strikes,’ which are strikes against ‘groups of men who bear certain signatures, or defining characteristics associated with terrorist activity, but whose identities aren’t known.’
Besides the above two categories, there are also reports suggesting that drone strikes are carried out against military-aged males who are present in a strike zone, and are thus deemed to be combatants because ‘simple logic indicates that people in an area of known terrorist activity… are probably up to no good.’ It is possible that this category may be a subset of signature strikes.
Beginning first with the issue surrounding ‘personality strikes’: despite the claim that the identity of the target is known to a ‘high degree,’ such strikes have failed to hit the correct target. For instance, high-profile leaders such as Osama bin Laden and Baitullah Mehsud were reported dead on more than one occasion resulting in the death of innocent civilians in their stead.
From 2008 onwards, the USA expanded their usage of drones by employing the strategy of ‘signature strikes’, which lowered the threshold for targeting individuals from those who were highly likely to be combatants, to those who merely displayed certain characteristics and were thus suspected to be combatants. This led to the proliferation of drone strikes, as then President Obama adopted an approach entailing that all military-age militants in a strike zone are presumed combatants unless there was explicit intelligence proving their innocence. This strategy is dubious on many accounts, not least because it reverses the presumption of innocence from ‘innocent until proven guilty’ to ‘guilty until proven innocent.’ This contradicts the rule contained in API entailing that in the presence of doubt, all individuals must be deemed civilians.
Notwithstanding, drone cameras can only accomplish so much, and states also rely on informants to gather intelligence. Yet, it is not clear that the armed forces of Al-Qaeda and related groups distinguish and identify themselves in a sufficient manner from civilians such as to facilitate the distinction and certainty that they are combatants. This affects the quality of intelligence that is relayed back to states by informants. Furthermore, obtaining intelligence in this manner is a difficult task; neither Pakistan nor the USA have a history of on-the-ground presence in regions where Al-Qaeda and related groups are said to be located, such as FATA.
Consequently, the effect of low-quality intelligence and methods utilised to carry out drone strikes is that such attacks do not strictly adhere to the principle of distinction, and thus have the corollary effect of causing many civilian casualties. For instance, during the era of predominant usage of ‘personality strikes’ – which are claimed to hold greater compliance to the principle of distinction than ‘signature strikes’ due to the near certainty of the target – a single drone strike in Bajaur (then administered under FATA) killed around 80 civilians, most of whom were children, in October 2006.
In addition, there is a lack of evidence to suggest that drone strikes cause fewer civilian casualties in comparison to other weapons. One classified study published by the Joint and Coalition Operational Analysis (JCOA) division of the US military observed that ‘drone strikes in Afghanistan were seen to have close to the same number of civilian casualties per incident as manned aircraft, and were an order of magnitude more likely to result in civilian casualties per engagement’, wherein incident is defined as situations resulting in the death of civilians, and engagement is defined as situations using drone strikes. Thus, as Dr. Mujtaba observes, ‘drone strikes killed on average as many civilians as manned aircraft in situations where they killed civilians… [and] caused civilian casualties more frequently than manned aircraft by ̳an order of magnitude.’ In fact, according to a press release in response to the study, drone strikes were ten times more likely to cause civilian casualties than manned aircrafts.
As for the reporting of civilian deaths which often relay low death counts, there is a lack of transparency surrounding how these deaths are calculated. To state one example, as mentioned earlier, the Obama administration classified civilians as combatants unless proven otherwise.
The future of drones
The perceived compliance of drones with the principle of distinction has led to the proliferation of their usage. In April 2021, President Biden announced an over-the-horizon counterterrorism policy. Some two months later, it was reported that CIA director William Burns had travelled to Pakistan to discuss counterterrorism cooperation between the two states. It is believed that the USA was seeking drone bases in Pakistan from which to carry out their operations against Al-Qaeda and related groups.
Whilst the current position of Pakistan in consenting to host bases for US drones is unclear, the fact remains that drones continue to be used and heralded for their IHL compliance. Some commentators such as Alston have argued that the USA is asserting an ‘ever-expanding entitlement’ for itself to target individuals across the world, and such norms may return to haunt the USA. Others have argued that the likelihood of this occurring is low. Nonetheless, it is clear that drone usage does not comply with the principle of distinction as readily as first envisaged. A closer inspection reveals the unstable foundations of this perceived compliance.
This article has attempted to demonstrate the pressure exerted on the principle of distinction – a core principle of IHL – by the use of drones. It has been argued that the usage of such weapons complies with IHL, more specifically, with the principle of distinction, as the precise technology of drones ensures that only lawful military targets are subject to attacks. However, a deeper examination reveals that this conclusion does not always hold. The consequence of interpreting the principle of distinction broadly by focusing on the precision and accuracy of the weapon as opposed to the precision and accuracy of the process employed for utilising the weapon, has the unintended consequence of proliferating drone strikes. This further has a domino effect in increasing the number of civilian casualties and in many cases, violating the principle of distinction altogether.
In a broader IHL context, the proliferation of drones imbues another unsettling realisation hinted at the beginning of this article: if there is no risk of death involved in conflict, then what is there to prevent a scourge of war? In his book, On Killing, Dave Grossman – a retired lieutenant colonel of the US Army – highlights how soldiers’ innate initial resistance to firing following WWII was overcome through the introduction of training measures, including video games. These measures increased soldiers’ firing rate in the Vietnam war to over 90 percent. It is difficult to ignore the similarity between contemporary drones and video games, to the extent that both involve human pilots and are remotely controlled. Yet, death ensuing from drone attacks in the ‘real world’ results in a permanent end. Is it possible that that this remote-control mentality is a cause for the increase in civilian casualties resulting from drone strikes as demonstrated in this paper? After all, video games sought to distant and desensitise soldiers from the immediate battle scene – a blinding similarity with how drones are operated today.
 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.
 Legality of the Threat or Use of Nuclear Weapons (Advisory Opinion),  ICJ Rep 226, 257, .
 Article 13(2), Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of Non-International Armed Conflicts (Protocol II), 8 June 1977, 1125 UNTS 609.
 Customary International Humanitarian Law, Vol. I, Henckaerts & Beck, ICRC (2009) (see http://www.icrc.org/customary-ihl/eng/docs/home)
 (n 2), .
 Article 48, API.
 Article 51(2), API.
 Article 52(1), API.
 Article 51(4), API.
 Michael W Lewis and Emily Crawford, ‘Drones and Distinction: How IHL Encouraged the Rise of Drones’ (2013) 44 Geo J Int’l L 1127, 1135.
 Article 51(3), API. The notion of taking ‘direct part in hostilities’ is disputed, but such an assessment is beyond the scope of this article. Further information may be found in the ICRC’s Interpretive Guidance (2009). Note that this guidance is not binding and not all states accept the interpretation provided by the ICRC.
 Article 43, API.
 Article 50, API.
 Gary Lilienthal, Nehaluddin Ahmad and Faizan Mustafa, ‘Drones: A symptom of regression in the principle of Distinction?’ (2018) 20(2) FlinLawJI 299, 322.
 Rudolf Peter, ‘Killing by Drones: The Problematic Practice of U.S. Drone Warfare’ (2014) 1 Ethics and Armed Forces 36, 36. Also see: (n 14), 20.
 Ahmad Mujtaba Siddiqi, ‘Drones do not contribute to counterinsurgency: an analysis of the strategic value and humanitarian impact of US drone strikes in Pakistan’ (2015) 25 ISSR 1, 42.
 See (n 16), Section 2: estimates of civilian deaths: a contested debate for a detailed statistical breakdown.
 See President Barack Obama, Remarks by the President at the National Defense University, Office of the Press Secretary, Washington, DC, 23 May 2013.
 Jelena Pejic, ‘Extraterritorial targeting by means of armed drones: Some legal implications’ IRRC (2015), 17.
 (n 10), 1153.
 (n 10), 1154.
 (n 2), .
 (n 2), .
 UNCHR, ‘Report of the Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions [Alston Report] (2010) A/HRC/14/24/Add.6, 
 Andrew Corr, ‘Unmanned, Unprecedented, and Unresolved: The Status of American Drone Strikes in Pakistan Under International Law’ (2011) 44(3) Cornell International Law Journal 729, 748.
 (n 16).
 (n 16), 9.
 Kevin Jon Heller, ‘One Hell of a Killing Machine’: Signature Strikes and International Law’ (2013) 11(1) Journal of International Criminal Justice 1, 2.
 Daniel Klaidman, Kill or Capture: The War on Terror and the Soul of the Obama Presidency (Harcourt, 2012), 41.
 (n 28), 11.
 (n 19), 27.
 (n 16), 9.
 Jane Mayer, ‘The predator war: what are the risks of the C.I.A.’s covert drone program?’ (The New Yorker, 19 October 2009) – example provided of a Predator drone killing three suspicious Afghans in 2002, one of whom was thought to be Osama Bin Laden. The victims were in fact innocent villagers gathering scrap metal.
 (n 16), 9.
 Jo Becker and Scott Shane, ‘Secret “kill list” proves a test of Obama’s principles and will’ (The New York Times, 29 May 2012)
 Article 50, API.
 (n 25), 749.
 (n 16), 42.
 (n 16), 11. Originally reported by Pakistani daily The News “Most Bajaur victims were under 20” (5 November 2006).
 (n 16), 46 referencing: Joint and Coalition Operational Analysis, “Drone Strikes: Civilian Casualty Considerations,” executive summary (2013).
 CVIC, ‘Drones More Likely to Harm Civilians than Manned Aircraft in Afghanistan’ (2013).
 (n 18).
 Remarks by President Biden on the Way Forward in Afghanistan, The White House Briefing Room (April 14 2021).
 ‘CIA chief told drone bases won’t be hosted’ (Dawn News, 9 June 2021)
 Press Release, Office of the High Commissioner for Human Rights [OHCHR], ‘UN Expert Criticizes “Illegal” Targeted Killing Policies and Calls on the US to Halt CIA Drone Killings’ (2 June,2010),
 (n 10), 1163.
 Dave Grossman, On Killing: The Psychological Cost of Learning to Kill in War and Society (1996).