In November 2002, a CIA drone armed with Hellfire missiles struck the car in which the mastermind of the attack against the USS Cole, affiliated to Al-Qaeda, was crossing the desert of Yemen.[i] Today the US is recognized to have two different targeted killing programs, one linked to operations in Afghanistan in support of US troops on the battlefield; the other, covert and managed by the Agency, in support of national foreign policy objectives abroad, focused on al-Qaeda elements in the tribal areas of Pakistan.[ii] Both are centred on drones.

Unmanned aerial vehicles (UAV) or drones, i.e. powered aerial vehicles piloted remotely,[iii] well-known as means of battlefield surveillance, today can carry a lethal or non-lethal payload. They began to serve in Afghanistan by early October 2001, when Operation Enduring Freedom started. Coalition forces are today deploying Predator MQ-1, armed with AGM-114 Hellfire missiles, for armed reconnaissance and engagement; And the MQ-9 Reaper, which can carry Hellfire anti-armour missiles and laser-guided bombs.[iv] Predators and Reapers are becoming essential resources in the counterinsurgency campaign.[v] They make possible unprecedented levels of surveillance and target acquisition, guaranteeing systematic and real time observation of the area of operations. Furthermore, they are successfully employed in support of ground troops who come under enemy fire and for the targeted killing of a specific individual. Equipped with precision ammunition, these platforms, lingering over targets for hours, unify the advantage of close air support conducted through conventional aircraft with a lower audible footprint.

The legality of drone strikes in the context of an armed conflict depends on interpretation of international humanitarian law, specifically those laws governing the conduct of hostilities. Unplanned and troops-in-contact interventions most risk contravening humanitarian law. To ensure legal conformity with the principles of discrimination, proportionality, necessity, and precaution, the rules of engagement require the positive identification of the target (PID). Although strikes on individuals carried out in self-defence, when troops come under attack or when terrorists are about to attack, are lawful, questions remain as to the use of excessive force and collateral damage, in terms of civilian casualties.

Drones have also successfully targeted senior terrorist figures in so-called “named killing” operations. In those cases, strikes require a vast work of intelligence for the identification of the target and its constant surveillance. Ground-level information has proved extremely important. Thus, in numerous cases there was time to elaborate a plan for the strike as well as plan a special operation to arrest the target. The targeted killing option prevails when the costs and benefits of a ground operation are considered unfavourable. That evaluation must stand the proportionality test, weighing anticipated military advantage against civilian deaths, as well as the principle of necessity and distinction. Violations of these standards make the operation illegal.

Collateral damage in the use of such sophisticated machines is one of their main constraints, even when their employment is formally consistent with international humanitarian law. Several reports have revealed a 1:50 casualties rate (for each targeted individual, there are 50 collateral casualties, not to speak of loss of property).[vi] Daniel Byman argued in Foreign Affairs that Predator attacks force the enemy to concentrate on defence rather than offense. Referring to operations conducted in the West Bank and Gaza, he observed that this positive outcome is confronted by the fact that Israel found it hard to kill terrorists only. [vii] According to the Israeli human rights organization B’Tselem, since the second Intifada (uprising) broke out in November 2000, the Israel Defense Forces (IDF) killed more than 300 Palestinians in targeted operations, more than 130 of whom were bystanders. In 2004, Sheikh Ahmed Yassin, the leader of Hamas, was killed in Gaza by a missile fired from an Israeli helicopter, together with seven other persons. In the air strike against Salah Shehadeh, the leader of Hamas’ military wing Iz Adin al-Kassam, sixteen civilians died. Planners did not use feasible precautions to avoid harming civilians, violating combatant-civilian distinction, and/or considered the collateral damage an acceptable price for the killing of senior militants, violating the right to life of relatives, bystanders and neighbours.

The extension of the battlefield beyond the effective zone of operations, implying a right to kill without warning the enemies of a state anywhere, seems to the Special Rapporteur for Extrajudicial Executions unjustified. In 2004, he defined the strike in Yemen as a clear case of extrajudicial killing.[viii] In the aftermath of the killing, The New York Times commented that “the missile strike represented a tougher phase of the campaign against terror and moved the Bush administration away from the law enforcement-based tactics of arrest and detention of al-Qaeda suspects that it had employed outside Afghanistan in the months since the fighting here ended.”[ix]

The use of force outside the real battlefield is regulated by human rights law and thus justified only if the targeted individual is about to kill someone. The terrorists killed in Yemen in 2002 were formally under the jurisdiction of Yemen, which had granted permission to the US operations. Formally, the suspects were not under US authority and control, since US representatives had not apprehended them. However, as Yemen did not have any control over the C.I.A.’s operation, they could be judged to be in the hands of the US, as a high–tech combat aircraft was tracking their car in order to assassinate them.[x] Since they were killed outside the zone of operation (Afghanistan), the employment of a lethal strike had to satisfy certain conditions. These were a threat to human life or integrity posed by the target, no reasonable alternative to the killing, and a use of force proportionate to the threat. At the time, these conditions were ignored.

In December 2009, the Obama administration authorized an expansion of the C.I.A.’s drone program in Pakistan's lawless tribal areas, in parallel with the decision to send 30,000 more troops to Afghanistan.[xi] The increase in the employment of this kind of weapon systems, considered as force multipliers in the zone of operations and actually stationed in Afghanistan, if used outside the battlefield, raises some questions.

In the Afghan war, the zone of operation coincides with the boundaries of that country, as US troops have a limited right to (hot) pursuit of the insurgents across its border and within Pakistan, where they may use only responsive force, as a form of self-defence, while ISAF cannot operate beyond the border. The use of drones within the zone of operation, by NATO-led ISAF or the US-led Enduring Freedom coalition, against those who directly participate in hostilities is legal. What the law does not permit is disproportionate force, and willful or reckless indiscriminate targeting.

In Pakistan, as well as in other hot spots of the globe outside the theatre of war, human rights should have primacy in regulating the employment of lethal weapons. In targeting al-Qaeda operatives, the US is exercising military force extraterritorially and outside the context of an armed conflict, and thus it has to implement the regime imposed by the International Covenant on Civil and Political Rights. Thus, the US should follow a law enforcement model, which imposes first a less rapid and more risky effort to arrest terrorists, reserving lethal strike for extreme situations justified by self-defence.

In law enforcement, a targeted killing is a lethal strike to defend a victim who is at risk of death or grave bodily harm, in an in extremis situation, and after the escalation of force which has precluded the non-lethal resolution.[xii] The use of force must be reasonably necessary and proportional to protect human life, considering that the deprivation of life of the attacker is arbitrary when the force used is disproportionate to the actual danger.

Due to those numerous constraints, to engage in targeted killing outside an armed conflict often equates to murder. Outside of warfare and the confines of military necessity, a strike would be a violation of the right to life of the targeted individual, and consequently an arbitrary killing.

Chronicles report a significant aerial campaign, devoted to tracking and killing terrorist operatives, along the permeable frontier between Afghanistan and Pakistan, and in the federally administered tribal areas of Pakistan. Those in favour of the employment of precision weapons to kill named enemy fighters recovering far from the battlefield focus on the value of the target, considered a public enemy whose killing is indispensable, while little attention is placed on his/her human rights. Worse, the rights of his/her relatives are not considered at all. In northwest Pakistan, society has a tribal structure and families are extended. People live concentrated in hamlets and compounds. Predators and Reapers are precision weapons platforms, but the radius of the blast of a Hellfire missile always includes those who are relatively close to the target, and the hit is capable of destroying an entire neighbourhood. A strike against a tribal leader normally kills his entire family. This is unacceptable under the law of human rights. It is true that often, a warlord rests and recovers with his lieutenants and this circumstance increases the value of the target. However, troops are not allowed to engage an individual on the mere suspicion of his being a potential or actual unlawful combatant.

There are frequent episodes in which insurgents or criminals in the service of drug lords participate directly in hostilities in Afghanistan. The use of drones against those entities is legal, subject to the restrictions of international humanitarian law, so long as the conflict endures. But the issue becomes problematic in two circumstances: i) when the target is individualised in a situation other than a combat engagement; ii) when the strike violates the criteria of distinction and proportionality or, when innocent civilians are subjected to the strike. Targeting a civilian who is not directly involved in combat is a violation of humanitarian law. When the use of such weapons causes an excessive toll in human casualties, it is also illegal. Further considerations concern human rights, as targeted killings against non-combatants result in violation of the norm that prohibits extrajudicial or arbitrary killing. Targeted killing is thus illegal, except in the narrowest of war-like conditions.

Strictly applied, international constraints on the use of military force against individuals would forbid nearly all real-world targeted killings. For this reason, the use of drones cannot be more than a tactic. Turning it into a strategy or policy is illegal and counterproductive. Killing the targeted and his/her relatives fails to provide an enduring advantage. It alienates populations and erodes support for counterinsurgency operations. Thus, even when lawful, the use of unmanned aerial vehicles to strike adversaries should be considered an extreme measure. It is necessary to refrain from the temptation of thinking that all is permitted in the ultimate war against terror, for reasons of humanity as well as efficiency.

Strikes conducted by the CIA have been openly publicized, as most of the world accepts as legitimate targeted killing of a terrorist.[xiii] However, the restraining effect of the principle of humanity becomes decisive where armed forces operate against selected individuals in situations comparable to peacetime policing,[xiv] or when they are trying to stabilize a country in order to create an endeavour in which the rule of law will flourish, such as in Afghanistan and, by connection, Pakistan.

[i] The Executive Order No. 12,333, (1981), reprinted in 50 U.S.C. § 401(2000), entitled 'United States Intelligence Activities', para. 2. 11 provides that “No person employed by or acting on behalf of the United States Government shall engage in, or conspire to engage in, assassination.”

[ii] J. Mayer, The Predator War, What are the Risks of the C.I.A.’s Covert Drone Program?, The New Yorker, Oct. 26, 2009, at 36.

[iii] The Department of Defense Dictionary of Military and Associated Terms 579, Joint Publication 1-02, April 12, 2001 (amended Oct. 17, 2008), cited in M. E. O’Connel, Unlawful Killing with Combat Drones  A Case Study of Pakistan, 2004-2009, Notre Dame Law School, Legal Studies Research Paper No. 09-43, at 3.

[iv] RQ-1 Predator is a long-endurance, medium-altitude unmanned aircraft system for surveillance and reconnaissance missions. See * URL http://www.airforce-technology.com/projects/predator/

[v] Us Army, FM 3-24/MCWP 3-33.5, Counterinsurgency (2006), at E-3.

[vi] M. E. O’Connell, Unlawful Killing with Combat Drones.  A Case Study of Pakistan, 2004-2009, Notre Dame Law School, Legal Studies Research Paper No. 09-43, at 10.

[vii] D. Byman, Taliban vs. Predator, available on Foreign Affairs, at URL http://www.foreignaffairs.com/articles/61513/daniel-byman/do-targeted-killings-work

[viii] UN Doc. E/CN.4/2003/3, 13 January 2003, at para. 39.

[ix] D. Johnston & D. E. Sanger, Fatal Strike in Yemen Was Based on Rules Set out by Bush, N.Y. Times, Nov. 6, 2002.

[x] According to Professor J. Paust, a person being targeted by a drone flying in the airspace of a foreign country is not within the jurisdiction, actual power, or effective control of the state using the drone. Therefore, human rights protections do not pertain. See J. J. Paust, Self-Defense Targeting of Non-State Actors and Permissibility of U.S. Use of Drones in Pakistan, J. Transnat'l L. & Pol'y, Vol. 19, 2010; U of Houston Law Center No. 2009-A-36. Available at SSRN: http://ssrn.com/abstract=1520717, at 27.

[xi] S. Shane, C.I.A. to Expand Use of Drones in Pakistan, N. Y. Times, December 3, 2009. On the implementation of a new strategy in Afghanistan, E. Schmitt, Elite U.S. Force Expanding Hunt in Afghanistan, N. Y. Times, 26 December 2009.

[xii] N. Melzer, Targeted Killing in International Law (OUP, New York 2008), at 59.

[xiii] M. Osiel, The End of Reciprocity (CUP, New York, 2009), at 387.

[xiv] International Committee of the Red Cross, Interpretative Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law, 27 (May 2009), at 80-81.