I. Summary
1. Limitations on the choice of methods and means of warfare can already be found in the oldest sources of international humanitarian law and were repeated and re-established in article 35 of the First Additional protocol (AP1). The preamble of the Convention on Certain Conventional Weapons refers to this article 35 as a general principle of law.
2. States must ensure that their methods and means of warfare are compatible with their obligations under international law. The prohibition in treaty and customary law to employ certain methods and means of warfare and the obligation to respect and apply international law in good faith already logically include an obligation to review (new) methods and means of warfare. This view is shared by the ICRC and in academic writing. For States Parties to the First Additional Protocol, this weapons review mechanism has been made explicit in article 36 of that Protocol.
3. The scope and elements of the weapons review process are subject to further study. Article 36 of the First Additional Protocol provides a sound basis for this study, from which it becomes clear that the following elements are important:
- “the study, development, acquisition or adoption”: The obligation to review the legality of a (new) method or means of warfare clearly applies whenever a State intends to acquire or adopt such a method or means, as the logical next step after that stage would be the employment or deployment of the method or means of warfare. Interpreting the scope of the obligation as regards the study and development of new methods and means of warfare is more complex and not internationally agreed upon. However, as an overall remark it can be demonstrated that the review should be carried out at the earliest possible opportunity.
- “new” (weapon, means or method of warfare): There seems to be a widespread agreement that the word “new” means “new for the State in question” whether or not bought from other States. Equally undisputed is the requirement that a (new) review takes place of methods or means of warfare following modification, even if the method or means of warfare was previously approved.
- “weapons, means or method of warfare”: Although apparently linguistically clear, the core component of the review requirement, that is what needs to be reviewed, is up for debate. However, regardless of the chosen approach, it appears clear that the wording of Article 36 was intended to be as broad and as all-inclusive as possible and that the review obligation is met if all weapons, applying a broad definition thereof, and all methods of warfare are subjected to review. And it would seem that the way a weapon is intended to be used would already be subjected to review as part of the review of the weapon itself.
- “in some or all circumstances”: A weapon must be reviewed not only “as such”, but also in relation to its intended use, making the review of “methods of warfare” in relation to that weapon to be an integral part of the weapon review. However, it is of considerable importance that the review is limited to the normal, expected or intended use of the weapon. Almost all of the relevant sources identify the possibility of misuse or inventive abuse of any weapon and the review need not take all of those possible alternatives into consideration.
- “any other rule of international law”: Acquiring and, certainly, deploying or using a weapon, method or means of warfare which would violate any of the rules of international law applicable to a State would constitute a violation of the law and it would seem logical that States are therefore under an obligation to include all relevant applicable international law in the equally logically mandatory review process.
II. Conclusions and recommendations
4. States must ensure that their weapons, means or methods of warfare are compatible with their obligations under international law. Therefore, States need to review new weapons, means or methods of warfare.
5. To enhance States’ capacities to fulfil their international obligation to review new weapons, means and methods of warfare, exchange of States’ national experiences with review procedures would be useful.
6. The encouragement of weapons review information exchange between States, which could contain national experiences/best practices on, amongst others, (1) implementation of the review process, (2) expertise and multidisciplinary teams for a weapon review and (3) reliability of review data.
III. Introduction: An Overview of Provisions on the Methods and Means of Warfare
Methods and means of warfare
7. Limitations on the choice of belligerents as regards methods and means of warfare can already be found in the oldest sources of international humanitarian law (IHL), including those which by themselves are not “law” but which may be considered precursors of later legal instruments in this regard. The earliest example can be found in section I, paragraph 16, of the Lieber Code:
“Military necessity does not admit of cruelty – that is, the infliction of suffering for the sake of suffering or for revenge, nor of maiming or wounding except in fight, nor of torture to extort confessions. It does not admit of the use of poison in any way, nor of the wanton devastation of a district. It admits of deception, but disclaims acts of perfidy; and, in general, military necessity does not include any act of hostility which makes the return to peace unnecessarily difficult.”
8. The earliest formulation of this principle in a legal instrument, and the inspiration for many of the later iterations of this rule, can be found in the preamble of the Declaration of St. Petersburg:
“That the only legitimate object which States should endeavour to accomplish during war is to weaken the military forces of the enemy; that for this purpose it is sufficient to disable the greatest possible number of men; that this object would be exceeded by the employment of arms which uselessly aggravate the sufferings of disabled men, or render their death inevitable; that the employment of such arms would, therefore, be contrary to the laws of humanity.”
9. Both of the elements set forth in the instruments presented above can be found as well in article 4 of the Oxford Manual,
“The laws of war do not recognize in belligerents an unlimited liberty as to the means of injuring the enemy. They are to abstain especially from all needless severity, as well as from all perfidious, unjust, or tyrannical acts.”
10. The Peace Conferences of The Hague of 1899 and 1907 resulted, inter alia, in the adoption of the Conventions and annexed Regulations that form the core of the element of IHL commonly referred to as “Hague Law”. Article 23, sub (e), of the Regulations,
“In addition to the prohibitions provided by special Conventions, it is especially forbidden(e) to employ arms, projectiles, or material calculated to cause unnecessary suffering.”
11. These early versions of the general rule regarding methods or means of warfare, including the prohibition on unnecessary suffering, were repeated and re-established in article 35 of the First Additional Protocol (AP1):
“1. In any armed conflict, the right of the Parties to the conflict to choose methods or means of warfare is not unlimited.”
12. This rule is followed by specific examples of prohibited forms or types of methods or means of warfare, including those causing unnecessary suffering (paragraph 2) or causing, intended or expected to cause widespread, long-term and severe damage to the environment (paragraph 3). Although not specifically mentioned in Article 35, it is also clear from several provisions of IHL, including Article 51, paragraph 4, of AP1, that the prohibition includes indiscriminate weapons.
13. As a final example of the principle of limitations on the choice of methods and means of warfare under international law, the preamble of the Convention on Certain Conventional Weapons (CCW)
14. In terms of customary law, the International Committee of the Red Cross established that the prohibition of methods and means of a nature to cause unnecessary suffering or superfluous injury and the prohibition to use weapons which are by nature indiscriminate are rules of customary international law, in both international and non-international armed conflicts.
15. It may be concluded from the (brief) historical overview of the law above, that the limitations imposed on the choice of methods or means of warfare not only encompasses means of warfare specifically prohibited or restricted by specific instruments of law,
IV. Legal Basis for the Obligation to Review
16. In view of the prohibition of certain (categories of) methods and means of warfare as set forth in the introduction above, both in terms of treaty law and customary law, two principal legal bases for an obligation to review (new) methods and means of warfare can be identified. Firstly, and quite obviously, for States Parties to the First Additional Protocol the obligation as set forth in Article 36 of AP1 is binding. Although it is recognized that not all States are a party to that Protocol, Article 36 will be used as the basis for the discussion of the scope and elements of the obligation to review (new) methods and means of warfare below. The reason for this is that it is easier to discuss the various aspects related to weapons review mechanisms on the basis of exact wording and practice and using a concrete, specific provision as a framework for that discussion.
17. Alternatively, a legal obligation for all States to review the legality of new methods and means of warfare can be based on the prohibition of certain (categories of) methods and means of warfare itself and the obligation to respect and apply international law in good faith.
18. While it would be beyond the scope of this paper to establish whether Article 36 of AP1 as that article is formulated has itself become part of customary law, it follows from the above that the obligation to review the legality of (new) methods and means of warfare is part of customary law and, although the scope and elements will be discussed in more detail below, would in any case encompass reviewing all new methods and means of warfare prior to their use or employment in order to ensure compliance with the obligations of the State in question under international law, as well as the circumstances under which such compliance might be called into question.
V. Scope and Elements of the Review Process
19. Article 36 of AP1 states:
“In the study, development, acquisition or adoption of a new weapon, means or method of warfare, a High Contracting Party is under an obligation to determine whether its employment would, in some or all circumstances, be prohibited by this Protocol or by any other rule of international law applicable to the High Contracting Party.”
20. The wording of this provision requires further examination of some of its components in order to establish the scope and elements to be included in a weapons review process or mechanism. The components in question are: (a) “the study, development, acquisition or adoption”; (b) “new”; (c) “weapon, means or method of warfare”; (d) “in some or all circumstances”; and (e) “any other rule of international law”.
A. The study, development, acquisition or adoption
21. The temporal component of the review obligation, that is the question when the review must be carried out, would seem to provide little opportunity for debate or question as regards the acquisition or adoption stages. Clearly the obligation to review the legality of a (new) method or means of warfare applies whenever a State intends to acquire or adopt such a method or means, as the logical next step after that stage would be the employment or deployment of the method or means of warfare. Ensuring legality prior to actual use would seem to be a self-evident requirement under international law, including IHL, as set out above. As regards the obligation to review new methods or means of warfare prior to the acquisition or adoption thereof, it should be pointed out that in these situations the review should be carried out at the earliest possible opportunity. The legal requirements for the State in question, including European Union requirements regarding public tenders, and the civil law requirements as regards the stage at which negotiations with commercial entities lead to financial obligations may have some impact on determining which stage is the most expedient for carrying out the review. In some cases, a review might be carried out in two or more stages, with initial advice being given in a more generic form as regards the type of weapon or system in question and more specific advice being given when the choice between available options becomes more specific.
22. A bigger challenge exists, however, as regards interpreting the scope of the obligation as regards the study and development of new methods and means of warfare.
23. The ICRC is quite clear that the obligation set forth in Article 36 not only encompasses existing methods and means of warfare (see also below as regards the “new” component), but also future weapons.
B. New
24. There appears to be little debate as regards the explanation of the word “new” as meaning “new for the State in question” and that the obligation to review new methods and means of warfare applies equally to existing (or even old) methods or (more likely) means of warfare acquired for the first time by the acquiring State, whether or not from other States.
25. Equally undisputed is the requirement that a (new) review takes place of methods or means of warfare following modification, even if the method or means of warfare was previously approved.
C. Weapon, means or method of warfare
26. Although apparently linguistically clear, the core component of the review requirement, that is what needs to be reviewed, can give rise to disagreements and confusion. This is not the result of over-ambitious legal analysis of the provision in question, but rather the result of discrepancies between the commendable intentions of the drafters of the text in question to be sufficiently inclusive in the scope of the review obligation on the one hand, and the different terminology used (and concomitant challenges faced) by those actually applying the review in practice.
27. The term “weapon” would seem to be the easiest of the three terms in question, yet already gives rise to some debate. From a tactical point of view, almost anything can be used as a weapon, while some of the less-lethal systems available on the commercial market (some even to private owners) are not readily or easily labeled as “weapons”, including by their manufacturers. Furthermore, even with more apparent and less disputable objects such as missiles or rockets, the question may be raised whether the “weapon” includes the platform from which it is launched, or only the actual projectile, or elements of both. In this case, the ICRC Guide and the ICRC Commentary do not provide much guidance. Academic literature indicates that in some States, definitions have been established as to what constitutes a “weapon” in the sense of the obligation to review,
28. Returning to the issue of platforms, the proposed definition (or approach) as regards the term “weapon” set forth above leads to the conclusion that platforms as such are not subject to review and, as will be explained further below, the general purpose and requirements of the review process make it difficult to envisage a meaningful review in the sense of the present discussion as regards a platform by itself (that is, devoid of any weapons as defined above). While most of the main weapon systems of any military platform rely on the targeting and launching elements of the platform’s (integrated or other) systems, most or perhaps all platforms may be outfitted with any variety of weapons and concomitant systems and such weapon systems
29. As regards “means” of warfare, this term can be found as well in Article 35 of AP1 which sets forth the general principle as discussed in part I of this paper. The confusing aspect of this term is that while Article 35 refers to “methods and means”, the addition of “weapon” in Article 36 renders the meaning of “means” unclear. The ICRC Commentary does not provide much help in this regard either, as it explains that “‘methods and means’ include weapons in the widest sense, as well as the way in which they are used.”
30. Finally, as regards “methods of warfare, ” the ICRC Commentary, the ICRC Guide and some authors interpret this concept as referring, at least in this context, to the way in which the weapons (and means of warfare) are used.
D. In some or all circumstances
31. The ICRC Commentary states that in the review of a weapon, the State must “analyse whether the employment of a weapon for its normal or expected use would be prohibited under some or all circumstances.”
32. Of considerable importance in reviewing a weapon and its intended use is that the review need only consider the normal, expected or intended use of the weapon. Almost all of the relevant sources identify the possibility of misuse or inventive abuse of any weapon and the review need not take all of those possible alternatives into consideration.
E. By this Protocol or by any other rule of international law
33. It was pointed out above that the obligation to review new methods and means of warfare follows from the obligations under customary law, at least as regards weapons. For States which are not party to Additional Protocol I, the first part of the element establishing what the weapons, methods and means of warfare need to be reviewed against would of course only apply as regards those parts of AP1 which are considered to be customary law. The second part of the element makes it clear, however, that the review obligation is not limited to AP1 but includes all rules of international law which are relevant in reviewing the weapon, method or means of warfare in question. Note that the provision does not limit the scope to instruments of IHL, thus also including all other elements and provisions of international law. Instruments to be considered include, consequently, the instruments listed in this paper, but also all weapon-specific or method-specific instruments such as the Protocols of the CCW, the Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques, etc., to which the State conducting the review is a Party, as well as all relevant rules of customary international law. Finally, it should be noted that the review not only includes specific provisions of international law related to individual weapons, etc., but also the more general prohibitions such as the one relating to weapons that are indiscriminate by nature or that cause superfluous injury and unnecessary suffering as set forth in the instruments discussed above.
34. Following the same legal logic as applied in the previous section of this paper, it would seem that the inclusive nature of this part of the provision of Article 36 is a self- evident obligation. States are under an obligation to abide by the rules of international law as applicable to them. Acquiring and, certainly, deploying or using a weapon, method or means of warfare which would violate any of the rules of international law applicable to that State would therefore constitute a violation of the law. Consequently, States are under an obligation to include all relevant applicable international law in the equally logically mandatory review process.
VI. Methodology and Composition of Weapon Review Mechanisms
35. Article 36 does not indicate how or by whom the review should be conducted and neither does the ICRC Commentary. Quite obviously, the ICRC Guide provides extensive advice and guidance on this aspect, which will not be repeated here. A few general observations and general principles regarding this aspect are worth discussing in this context, however.
A. Expertise and multidisciplinary review
36. Conducting a full review of a weapon, ammunition or other means of warfare requires knowledge of both the law and of the technical and operational aspects of the subject of the review. Depending on the nature of the weapon, ammunition, etc., medical knowledge or other specific expertise may also be required to evaluate and properly assess whether the object under review is compatible with the international law obligations of the State in question. Although not impossible, it would seem at least unlikely that a single person can possess all the requisite categories of expertise to the level required to conduct a full review. Consequently, regardless of whether the review is carried out by a single person or by a committee, a multidisciplinary approach or access to the various relevant areas of expertise is required at some stage in the process.
27. The expertise required to carry out the evaluation extends not only to the (mechanical, electronic, etc.) functioning of the weapon or means of warfare but also to the effects thereof on persons, objects, the environment, etc., as part of its normal functioning. This applies to methods of warfare as well, mutatis mutandis. These effects are relevant for evaluating the device in connection with certain specific provisions of international law, but also for the evaluation of whether the device causes superfluous injury or unnecessary suffering and can be limited as required by the principle of distinction.
B. Reliability of data
38. Conducting a full review in compliance with the legal obligation under discussion requires the use of reliable data. While this statement may seem self-evident, it is equally self-evident that the review often needs to be undertaken at an early stage in the procurement process, before testing can be conducted. In such cases, the reviewer must seek such data from other sources and must ensure that those sources are reliable. While a wealth of information, including complex technical data on a variety of weapons and ammunition, is available on the internet, it goes without saying that not all such information meets the requirements of a review. Similarly, while many manufacturers either provide or are willing to provide the type of data or information required to carry out a proper review, care should obviously be taken with regard to the objectivity of such data or information. Prior experience with select manufacturers may to some extent mitigate this factor, just as prior experience with other States may make it possible to use the data or information, or even the outcome of prior reviews of the object in question by those States, to the extent that those other States are willing to share or disclose such information. It is ultimately up to the reviewing State, however, to ensure that the review is carried out in such a way that the State can be satisfied that its obligation to review has been met.
C. Compliance with the review process and outcome
39. Quite clearly, States can only expect to be able to abide by the review obligation if the personnel in charge of procurement, acquisition, development, etc., of weapons, methods and means of warfare are aware of the requirement for review. While there are many ways to achieve this, making the review a mandatory step in the development and procurement of new weapons is a simple and effective method.
D. Communication
40. There is no duty to disclose or publish the outcome of the review process,
Weapons review mechanisms: submitted by the Netherlands and Switzerland (7 November 2017) CCW/GGE.1/2017/WP.5
