Over the last decade, Unmanned Aerial Vehicles (UAVs), or ‘drones’, have become the United States’ (U.S.) preferred military tool for fighting al Qaeda and other terrorist groups, used in all major military conflicts and crisis regions of the world, such as Iraq, Libya, Somalia and Yemen, yet mostly in the Afghanistan-Pakistan region. Although their use as a military tool is only part of a wider, highly emotional debate about the use of force against non-state actors across national borders, global attention has focused on such operations. After denying for many years that these attacks do take place, the U.S. administration has recently admitted to conduct such operations, defending them as a legal and legitimate response to terrorist threats. The chapter finds that amidst the heated discussion about the use of drones, it is often forgotten or misunderstood in which ways the state can react to transnational terrorism.
In the first step of the analysis, it is discussed whether the laws of war can be applied to the transnational fight against terrorism or if it has to be seen under human rights law, which would put much stronger restraints on the use of force. It is argued that the law-enforcement paradigm is very difficult in dealing with terrorist threats originating from areas which are no longer under government control. On the one hand, law-enforcement agencies of the victim state are often unable to operate in foreign countries. On the other hand, if the host government attempts to use law-enforcement measures, the backlash from the militants is more likely to create more of a quagmire than if a concerted and limited military action, such as a drone attack, were taken. Therefore, it is the most sensible option to assess the drone strikes is under the laws of armed conflict and not human rights law, as it is too domestic in nature to apply to the fight against international terrorism and does not allow appropriate means.
This raises important questions about the violation of Pakistan’s sovereignty, as Article 2 (4) of the UN Charta prohibits the “use of force against the territorial integrity or political independence of any State”. An exception to this prohibition is Article 51, which allows self-defence against an armed attack, yet it is not clear whether any action of self-defence has to be in response to an armed attack imputable by another state. In the traditional interpretation of the ICJ and customary international law, Article 51 does not warrant a right to self-defence against non-state actors, unless they are imputable to another state. Yet, as it is argued in the chapter, in recent years there has been change. Article 51 is now more and more interpreted in the way that states must be able to defend themselves against terrorist threats, hence allowing transnational use of force against terrorists. However, to limit risk of abuse against Article 2 (4), the strict rules of customary law need to be applied. These are the principles of immediacy, necessity, and proportionality.
Applied to the cross-border use of drones by the U.S. military against terrorists based in Pakistan, the chapter maintains that the overwhelming majority of U.S. incursions into Pakistani territory are illegal under international law because they do not meet these strict constraints of customary international law. However, targeted killings are not per se illegal, if the United States can prove – in each individual case – that an operation meets the requirements.