In conducting the bin Laden raid, the United States acted in full compliance with the legal principles previously set forth in a speech that I gave to the American Society of International Law on March 25, 2010, in which I confirmed that “[i]n …all of our operations involving the use of force, including those in the armed conflict with al-Qaeda, the Taliban and associated forces, the Obama Administration is committed by word and deed to conducting ourselves in accordance with all applicable law.” . . . .
Given bin Laden’s unquestioned leadership position within al Qaeda and his clear continuing operational role, there can be no question that he was the leader of an enemy force and a legitimate target in our armed conflict with al Qaeda. In addition, bin Laden continued to pose an imminent threat to the United States that engaged our right to use force, a threat that materials seized during the raid have only further documented. Under these circumstances, there is no question that he presented a lawful target for the use of lethal force. . . . Moreover, the manner in which the U.S. operation was conducted—taking great pains both to distinguish between legitimate military objectives and civilians and to avoid excessive incidental injury to the latter—followed the principles of distinction and proportionality described above, and was designed specifically to preserve those principles, even if it meant putting U.S. forces in harm’s way. Finally, consistent with the laws of armed conflict and U.S. military doctrine, the U.S. forces were prepared to capture bin Laden if he had surrendered in a way that they could safely accept. The laws of armed conflict require acceptance of a genuine offer of surrender that is clearly communicated by the surrendering party and received by the opposing force, under circumstances where it is feasible for the opposing force to accept that offer of surrender. But where that is not the case, those laws authorize use of lethal force against an enemy belligerent, under the circumstances presented here.In sum, the United States acted lawfully in carrying out its mission against Osama bin Laden. (Harold Hongju Koh, The Lawfulness of the U.S. Operation Against Osama bin Laden, Opinio Juris, May 19, 2011.)
States should publicly identify the rules of international law they consider to provide a basis for any targeted killings they undertake. They should specify the bases for decisions to kill rather than capture. They should specify the procedural safeguards in place to ensure in advance of targeted killings that they comply with international law, and the measures taken after any such killing to ensure that its legal and factual analysis was accurate and, if not, the remedial measures they would take. If a State commits a targeted killing in the territory of another State, the second State should publicly indicate whether it gave consent, and on what basis.
• States should make public the number of civilians collaterally killed in a targeted killing operation, and the measures in place to prevent such casualties.
• The High Commissioner for Human Rights should convene a meeting of States, including representatives of key military powers, the ICRC and human rights and IHL experts to arrive at a broadly accepted definition of “direct participation in hostilities.”
Specific requirements under human rights law, applicable in and outside armed conflict, include:
• States should disclose the measures taken to control and limit the circumstances in which law enforcement officers may resort to lethal force. These include:
• Permissible objectives (which may not include retaliation or punishment but must be strictly to prevent the imminent loss of life);
• the non-lethal tactics for capture or incapacitation that must be attempted if feasible;
• the efforts that must be made to minimize lethal force, including specifying the level of force that must be used at each stage;
• the legal framework should take into account the possibility that a threat may be so imminent that a warning and the graduated use of force are too risky or futile (e.g., the suspect is about to use a weapon or blow himself up). At the same time, it must put in place safeguards to ensure that the evidence of imminence is reliable, based on a high degree of certainty, and does not circumvent the requirements of necessity and proportionality.
• Disclosure of the measures in place to provide prompt, thorough, effective, independent and public investigations of alleged violations of law.
• The appropriate measures have been endorsed in the Principles on the Effective Prevention and Investigation of Extra-legal, Arbitrary and Summary Executions. These should guide States whenever they carry out law enforcement operations, including during armed conflicts and occupations. The State’s duty to investigate and prosecute human rights abuses also applies in the context of armed conflict and occupation.
Specific requirements under IHL, applicable in armed conflict, include:
• Disclosure of the measures in place to investigate alleged unlawful targeted killings and either to identify and prosecute perpetrators, or to extradite them to another State that has made a prima facie case for the unlawfulness of a killing.
• Ensure that State armed forces and agents use all reasonably available sources (including technological ones such as intelligence and surveillance) to obtain reliable information to verify that the target is lawful. These measures, which should be publicly disclosed to the extent consistent with genuine security needs, include:
• State armed forces should have a command and control system that collects, analyzes and disseminates information necessary for armed forces or operators to make legal and accurate targeting decisions.
• Targeted killings should never be based solely on “suspicious” conduct or unverified – or unverifiable – information. Intelligence gathering and sharing arrangements must include procedures for reliably vetting targets, and adequately verifying information.
• State forces should ensure adequate intelligence on the effects of weapons to be used, the presence of civilians in the targeted area, and whether civilians have the ability to protect themselves from attack. It bears emphasis that State forces violate the IHL requirements of proportionality and precaution if they do not do everything feasible to determine who else is, or will be, in the vicinity of a target – and thus how many other lives will be lost or people injured – before conducting a targeted killing.
• In the context of drone attacks and airstrikes, commanders on the ground and remote pilots may have access to different information (e.g. based on human intelligence, or visuals from satellites); it is incumbent
on pilots, whether remote or not, to ensure that a commander’s assessment of the legality of a proposed strike is borne out by visual confirmation that the target is in fact lawful, and that the requirements of necessity, proportionality and discrimination are met. If the facts on the ground change in substantive respects, those responsible must do everything feasible to abort or suspend the attack.
• Ensure that compliance with the IHL proportionality principle is assessed for each attack individually, and not for an overall military operation.
• Ensure that even after a targeting operation is under way, if it appears that the target is not lawful, or that the collateral loss of life or property damage is in excess of the original determination, targeting forces have the ability and discretion to cancel or postpone an attack.
• Ensure procedures are in place to verify that no targeted killing is taken in revenge, or primarily to cause terror or to intimidate, or to gain political advantage.
• Especially in heavily populated urban areas, if it appears that a targeted killing will risk harm to civilians, State forces must provide effective advance warning, as specifically as possible, to the population.
• Warning does not, however, discharge the obligation to distinguish between lawful targets and civilians.
• Although the use of civilians as “shields” is prohibited, one side’s unlawful use of civilian shields does not affect the other side’s obligation to ensure that attacks do not kill civilians in excess of the military advantage of killing the targeted fighter. (Philip Alston, Report of the Special Rapporteur on extrajudicial, summary or arbitrary executions, supra, paragraph 93).