By: John Balbona*

An important issue facing the United States (U.S.) and the international community as a whole is the role that unmanned aerial vehicles, also known as “drones,” should play in the fight against terrorism. Specifically, whether the use of drones for targeted killings of non-state actors within foreign countries is permissible by international law. The recent U.S. airstrike on a hospital in Afghanistan highlights how high the stakes involved in such the use of such tactics are when non-state enemy combatants are thought to be hiding within civilian areas.[1]

Since 2004, the U.S. has used drones to target and kill radical Islamic terrorists by means of targeted airstrikes throughout various countries of the Middle East and Northern Africa.[2] Proponents of the drone program argue that this program saves lives of American citizens while keeping American troops out of harm’s way.[3] However, despite its efficacy at targeting and killing enemy combatants, the U.S. drone program has been the subject of much criticism.

The first Additional Protocol to the Geneva Conventions (AP I) requires that parties to a conflict “at all times distinguish between the civilian population and combatants, and between civilian objects and military objectives.”[4] AP I also addresses the non-combatants in close proximity to the conflict in Article 51 by requiring parties to ensure that “[t]he civilian population and individual civilians . . . enjoy general protection against dangers arising from military operations,” and “not be the object of attack.”[5] Additionally, Article 51(3) forbids the targeting of civilians “unless and for such time as they take a direct part in hostilities.”[6] In order to comply with the principle of distinction, only combatants or military objectives may be targeted by drone strikes. Civilians or civilian objects are forbidden from targeting, unless the civilian or object has forfeited his or her protected status by participating in the hostilities.[7]

There are several practices by the U.S. that appear to be at odds with the requirements of the principle of distinction, and one such practice is the use of signature strikes. Signature strikes are targeted airstrikes in which the U.S. intelligence does not know the identity of the target, but instead identifies and kills its target “based on indications that people on the ground were likely with Al Qaeda or allied militant groups.”[8] These indications are “based on a ‘pattern of life’ analysis – intelligence on their behavior suggesting that an individual is a militant.”[9] This practice is problematic, because it runs counter to Article 51’s requirement that civilians enjoy general protection against the dangers arising from drone strikes.[10]

If the U.S. does not know the identity of the group it is targeting, then it does not know whether any civilians will be the objects of its attack. By not identifying the target of a signature strike, the U.S. is turning a blind eye to the actual identity of the target and relying upon others factors, which may lead to the deaths of civilians. “[T]he joke [i]s that when the C.I.A. sees ‘three guys doing jumping jacks,’ the agency thinks it is a terrorist training camp.” [11] Christof Heyns, U.N. Special Rapporteur on extrajudicial, summary, or arbitrary executions, argues that the proper standard for attacking a person under the laws of war is whether the person has a “continuous combat function” or is “directly participating in hostilities.”[12] Thus, Heyns argues, if a signature strike “target[s] without sufficient information to make the necessary determination, it is clearly unlawful.”[13]

Another problematic strategy of the U.S. drone program is the practice known as “double tap.” This tactic involves the “targeting those who have come in to help those who are injured” after a previous drone strike.[14] “Double tap” faces exactly the same issues presented by the practice of signature strikes; however, this practice is even more controversial, because targeting first responders cannot have the same justification as targeting enemy combatants using signature strikes. Signature strikes are justified through the ‘pattern of life’ analysis that at least requires the C.I.A. to point to factors that led them to believe the target was a military combatant.[15] The first responders who are targeted were likely never subjected to such scrutiny and were targeted merely because of their impulse to help. The principle of distinction requires that civilians or civilian objects are not targeted, unless the civilian or object has forfeited his protected status by participating in the hostilities.[16] The practice of double tap targets civilians and civilian objects without any attempt to distinguish from combatants, and, therefore, does not comply with the principle of distinction.

This is not to say that the U.S. drone program can not comply with international law and human rights. Ryan J. Vogel sets out ten guiding principles for conducting drone strikes within the letter and spirit of the Law of War.[17] The problem facing the U.S. drone program is its use of tactics that seemingly run counter to that letter and spirit. Despite the success of the U.S. drone program at killing enemy combatants, the U.S. should not lose sight of its mission and ideals by adopting practices that target unidentified individuals. Such practices will likely lead to the unnecessary deaths of innocent civilians, which alternative approaches could prevent. Not only does this collateral damage lead to potential breaches of international humanitarian law, but it also compounds the problem of terrorism by leading more people to extremism. Therefore, it is extremely important the U.S. reign in its controversial drone tactics to the confines of the letter and spirit of international law.

[1] Glenn Greenwald, The Radically Changing Story of the U.S. Airstrike on Afghan Hospital: From Mistake to Justification, The Intercept (Oct. 5, 2015),

[2] Peter Bergen & Katherine Tiedemann, Washington’s Phantom War, Foreign Affairs, July/Aug. 2011 Issue,

[3] Robert Weiner & Tom Sherman, Drones Spare Troops, Have Powerful Impact, San Diego Union Tribune (Oct. 9, 2014),

[4] Ryan J. Vogel, Drone Warfare and the Law of Armed Conflict, 39 Denv. J. Int’l L. & Pol’y 101, 116 (2010).

[5] Id.

[6] Id at 117.

[7] Id at 118.

[8] Scott Shane, Drone Strikes Reveal Uncomfortable Truth: U.S. Is Often Unsure About Who Will Die, N.Y. Times (Apr. 23, 2015),

[9] Glenn Greenwald, Three Key Lessons from the Obama Administration’s Drone Lies, The Guardian (Apr. 11, 2013),

[10] Vogel, supra note 4.

[11] Jo Becker & Scott Shane, Secret ‘Kill List’ Proves a Test of Obama’s Principles and Will, N.Y. Times (May 29, 2012),

[12] Steve Coll, The Unblinking Stare, New Yorker (Nov. 24, 2014),

[13] Id.

[14] Tara McKelve, Drones Kill Rescuers in ‘Double Tap,’ Say Activists, BBC News (Oct. 22, 2014),

[15] Greenwald, supra note 9.

[16] Vogel, supra note 4, at 118.

[17] Vogel, supra note 4, at 189.

* Edited by Christine Sanders