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CCW GGE: Potential Challenges Posed by Emerging Technologies in the Area of LAWS to IHL
March 27, 2019

Convention on Certain Conventional Weapons Group of Governmental Experts on emerging technologies in the area of LAWS
Potential challenges posed by emerging technologies in the area of LAWS to IHL
Geneva, March 26, 2019

Paula Marshall (as prepared)

Mr. Chair, let me briefly address some of the questions in the program of work before expounding in a bit more detail how legal reviews can contribute to IHL compliance.

With regard to the Chair’s first question, our view is that autonomous functions in weapons systems do not inherently pose a problem with respect to the application of IHL principles in carrying out attacks in armed conflict. As we noted yesterday, autonomy can at times facilitate greater compliance with IHL, including the potential to mitigate risks to civilians.

With regard to the Chair’s second question, we do not believe that autonomous functions in weapon systems inherently pose a problem with respect to the maintenance of combatant and commander responsibility for decisions to use force.

Responsibility for decisions to use force exists regardless of whether the weapon systems employed have autonomous functions.  Commanders do not absolve themselves of responsibility by using a weapon system with autonomous functions.

When using weapons systems with autonomous functions, the commander must make the legal judgments required by IHL, including by the principles of distinction and proportionality. The human operators of the system and their superior commanders are responsible and accountable for their use of the system, even if that system has sophisticated autonomous functions.

As we have described in working papers and previous interventions, the use of autonomous functions in weapon systems could enhance the implementation of combatant and commander’s intentions in using force in armed conflict.  In that sense, autonomous functions in weapon systems could strengthen responsibility for decisions to use force by making the results of those decisions more consistent with the intent of the decision-maker.

We have also noted in our working for this meeting how autonomous functions in weapon systems could facilitate the investigations of combat operations, for example, through the automated creation of logs recording the operation and use of the weapon system.  In this way too, autonomous functions in weapon systems could also strengthen mechanisms for accountability over decisions to use force.

With regard to the Chair’s third question, the U.S. military has long used the fundamental principles of law of war as a general guide for conduct during war, when no more specific rule applies. These principles are:  military necessity, humanity, distinction, proportionality, and honor.

As we have discussed in previous working papers and interventions, we believe that the Martens Clause reinforces the need to apply these customary international law principles when no more specific provision applies.  The Martens Clause does not impose a separate requirement apart from existing customary international law.

Now, we would like to discuss in depth the chair’s fourth question regarding the legal review of weapons.  We appreciate the constructive proposal by Argentina on this issue, which we are considering closely.

Reviewing the legality of weapons is a best practice for implementing customary and treaty law relating to weapons and their use in armed conflict.  The United States is not a party to the 1977 Additional Protocol I to the 1949 Geneva Conventions and therefore is not bound by that instrument, but we note that Article 36 of that Protocol creates an obligation for its Parties with respect to the study, development, acquisition, or adoption of a “new” weapon, means, or method of warfare.

Under U.S. Department of Defense policies, legal reviews are conducted as part of the broader acquisition processes.  In particular, a DoD policy (DoD Directive 5000.01) requires that the acquisition and procurement of DoD weapons and weapon systems be consistent with all applicable domestic and international law, including the law of war.  To implement this requirement, DoD Directive 5000.01 provides that “[a]n attorney authorized to conduct such legal reviews in the Department shall conduct the legal review of the intended acquisition of weapons or weapons systems.”

Legal advice on the intended acquisition of weapons ordinarily may be provided at different stages in the process of acquiring such weapons.  For example, under DoD policy on the use of autonomy in weapon systems (DoD Directive 3000.09), legal review and advice are provided before formal development and again before fielding with regard to certain types of weapon systems that involve the use of autonomy.

For the U.S. Department of Defense, the legal review of the acquisition or procurement of a weapon generally focuses on whether the weapon is illegal per se– whether a treaty to which the United States is a party or customary international law has prohibited its use in all circumstances. The use of autonomy to aid in the operation of weapons is not illegal per se.

Law of war issues related to targeting generally are not determinative of the lawfulness of a weapon.  A legal review of a weapon should consider whether the weapon is “inherently indiscriminate,” i.e., whether the weapon is capable, under any set of circumstances and in particular the intended concept of employment, of being used in accordance with the principles of distinction and proportionality.  Nevertheless, most targeting issues (e.g., whether a weapon would be used consistent with the requirement that attacks may only be directed against military objectives) are only capable of determination when presented with the facts of a particular military operation.

Weapons that use autonomy in target selection and engagement seem unique in the degree to which they would allow consideration of targeting issues during the weapon’s development.  For example, if it is possible to program how a weapon will function in a potential combat situation, it may be appropriate to consider the law of war implications of that programming.  In particular, it may be appropriate for weapon designers and engineers to consider measures to reduce the likelihood that use of the weapon will cause civilian casualties.

Under DoD policy, autonomous and semi-autonomous weapons systems go through “rigorous hardware and software verification and validation (V&V) and realistic system developmental and operational test and evaluation (T&E).”  Although rigorous testing and sound development of weapons are not required by the law of war as such, these good practices can support the implementation of law of war requirements.  Rigorous and realistic testing standards and procedures can ensure that commanders and national security policy makers can have a reasonable expectation of the likely effects of employing the weapon in different operational contexts.  In addition, such practices can help reduce the risk of unintended combat engagements, such as weapons malfunctions that could inadvertently cause harm to civilians.