It is a privilege to be part of the Sutton Colloquium, one of the most important discussions of international law that occurs in the United States. I would like to express sincere thanks to Professors Ved Nanda and David Akerson for inviting me, as well as to their students and staff for organizing the event.
My remarks concern this question: When may a state lawfully resort to drone attacks? The answer lies in the first instance in what we call the jus ad bellum, the law governing resort to military force. This is a distinct body of law with important overlaps with jus in bello, another body of law also known as international humanitarian law (IHL) or the law of armed conflict (loac), which governs how force is used once an armed conflict is underway. (1) We must begin with the jus ad bellum, however, analyzing whether resort to weaponized drones is lawful before turning to the jus in bello, to determine whether the way drones are used is lawful)
Drones are unmanned aerial vehicles that are operated by a pilot who may be thousands of miles away from where the drone is flying. (3) The militaries of sovereign states and of non-state actors are quickly acquiring large fleets of drones. Most of these drones are currently used for surveillance only. Increasingly, however, states and non-state actors are acquiring drones equipped with missiles and bombs, the sort of weapons that international law restricts to armed conflict hostilities. The restriction on weaponized drones to use in combat zones means that the distinction between situations of armed conflict and situations that are not armed conflict is critical. What exactly distinguishes these situations is a matter of common sense that is reflected in the definition of armed conflict found in international law. Armed conflict is the exceptional situation, while peace is the normal situation. Thus, whether the United States or any state is lawfully using armed drones depends on whether the initial resort to armed force is lawful or whether the use is within a situation defined by international law as an armed conflict.. Outside of armed conflict such use would be unlawful.
Before going into more detail respecting the law on resort to drones, I will first provide a brief history and very brief overview of drone use by the United States from 2001-2010. This history will set the stage for our discussion of the applicable law.
At the time of this writing, the United States has two types of combat drones in its arsenal: the MQ-1 or Predator and the MQ-9 or Reaper. (4) Predators began as surveillance drones and then were adapted to carry two Hellfire missiles. (5) The Reaper is similar in design and function to the Predator, but was specially designed as a launch vehicle for weapons. It can carry up to fourteen Hellfire missiles and 500-pound bombs. (6) The U.S. is rapidly increasing its supply of drones and will soon have more unmanned than manned aerial vehicles in its arsenal. (7) I understand pilots are not altogether happy with this development.
The United States is not the only country that possesses this technology. Other states and non-state actors have drones, including the United Kingdom, France, Russia, Turkey, India, China, Hezbollah, Israel, and Iran. (8) An October 2010 report by United Press International (UPI) says that Israel has sold drones to over 42 states. (9) Iran is also supplying drones to friendly states and non-state actors. In a New Yorker magazine article in late 2009, Jane Mayer described the U.S. as having two drone programs: one conducted by the U.S. Air Force and one by the CIA. (10)
From my discussions with others, especially with a former commander of drone operation at Nellis Air Force Base in Nevada, it is clear to me that all drone operations are today and probably for some time have been joint operations. None are carried out by the Air Force alone. The commander told me that "a thousand people see the video feed" from the deployed drones, from the pilots in their trailers in Nevada and New Mexico to intelligence analysts at CENTCOM to personnel in Japan to the President of the United States.
The first known use of a drone to kill a named individual occurred in Afghanistan in November 2001. This was about a month after the United States and the United Kingdom launched the intervention of October 7, 2001, in response to the 9/11 attacks. In the midst of armed conflict hostilities, the U.S. Air Force used a drone to launch a Hellfire missile to kill Mohamed Atef, a reputed al Qaeda leader, in his home near Kabul. (11) On November 3, 2002, the U.S. used a drone outside of a combat area to launch Hellfire missiles at a passenger vehicle traveling in a thinly populated region of Yemen. The CIA operated that drone from a base in Djbouti on Africa's east coast. (12) The United States Air Force at the time had control of drone operations, but did not carry out the strike because of concerns about its legality. The CIA apparently had no such concerns and carried out the strike killing all six persons in the vehicle, including a suspected top operative in al Qaeda and a United States citizen, a young man in his twenties from Buffalo, New York. (13) According to Dina Temple-Raston of National Public Radio, the CIA quickly arrived at the site, repelled an agent down, and took DNA samples from the bodies to confirm who had been killed. (14)
In January 2003, the United Nations Human Rights Commission received a report on the Yemen strike from its special rapporteur on extrajudicial summary or arbitrary killing. She concluded that the strike constituted "a clear case of extrajudicial killing." (15) Drone attacks by the United States in Pakistan began in 2004. (16) The number of attacks have jumped dramatically to about 30 in 2008 and continued to climb in 2009 to about 50. (17) In 2010, the U.S. attacked in Pakistan about 120 times. (18)
The U.S. has also been using drones in Somalia, a place that almost never gets mentioned in discussions of U.S. use of military force. (19) I have been unable to pinpoint when U.S. drone use in Somalia first began, but I have found news accounts that the U.S. was using drones in late 2006, perhaps to assist Ethiopia in the invasion that it carried out to attempt to install a new government in Somalia. (20)
Despite the fact that we refer to drones as "unmanned," there are people involved in all of these drone operations. There are people associated with drone use in Afghanistan, Djibouti, Pakistan, Yemen, and places where the drones have been housed such as Uzbekistan.
Many of these persons are CIA personnel or individuals under contract with the CIA. John Radsan, a former assistant general counsel at the CIA, has related to me that all decisions to actually fire a missile or drop a bomb from a drone are made by the CIA at its headquarters in Langley, Virginia. (21) Jane Mayer's article also confirms that the CIA is using private military contractors to assist with its drone operations. (22) While I certainly do have concerns about the CIA and private military contractors being involved in the use of lethal force, I do not think that is the most important issue confronting the United States as a matter of law today with respect to drone use. The U.S. could easily return all drone operations to the military. The most serious issue with respect to drones is the amount of firepower involved--drones are currently configured as military weapons, meaning resort to drones is lawful in only four circumstances.
First, military force may be used as part of a lawful exercise of individual or collective self-defense under the United Nations (UN) Charter Article 51. Second, the United Nations Security Council may authorize military force. Third, military force may be used by a government in effective control of a state to suppress an organized armed uprising within a state where military force is resorted to by rebel armed forces. Fourth, military force may be used by a state asked to join in suppressing an insurrection within another state. (23)
A drone is the aerial equivalent of a ground-based missile launcher or bomber aircraft. The police do not deploy this type of force--police do not get to drop bombs or use Hellfire missiles against criminal suspects. In law enforcement, lethal force is restricted to situations of absolute necessity. (24) Civilian casualties are not tolerated. There is no principle of proportionality that applies to the police when they are exercising lethal force. (25) Armed drones are therefore lawful only in armed conflict hostilities. The right to resort to them must be found in the law governing resort to military force, the jus ad bellum. The way they are used must be based on IHL and human rights.
Article 2(4) of the UN Charter is the most important rule on resort to force. (26) Itis a treaty rule that is binding on all sovereign states. Treaty rules are not easily changed by contrary state practice, despite what some commentators argue. Rather, such contrary state practice is a treaty violation according to the law of treaties. (27) Contrary state practice might be relevant to the formation of a rule of customary international law. (28) In the case of Article 2(4), however, not only are we talking about a treaty rule, the United States argued in its memorials in the Nicaragua case in 1984 that it is a rule of jus cogens. (29) In other words, Article 2(4) is a peremptory rule that cannot be overcome by a contrary treaty rule, let alone a new rule of customary law derived from state practice.
In addition to arguing that 2(4) has been changed by state practice, some scholars try to interpret it as allowing more than it does. (30) Article 2(4) is properly interpreted as prohibiting all uses of force above a certain de minimis level. Minimal uses of force such as firing a bullet across a boundary or across the bow of a ship may perhaps violate the principle of non-intervention, but...