Arms transfers to parties to armed conflict: what the law says

What are the humanitarian concerns raised by arms flows into conflict areas?

Though the international arms trade has never been as extensively regulated as it is today, weapons and munitions continue to flow, overtly and covertly, to some of the most brutal armed conflicts.

Such transfers contribute to the widespread availability and misuse of weapons, which exacts an unacceptable human toll in terms of lives lost or permanently altered by injury or trauma and loss of livelihoods, with civilians bearing the brunt of the violence. Inadequately controlled arms supply to parties to armed conflict facilitates violations of international humanitarian law (IHL) and international human rights law and hampers the delivery of life-saving humanitarian aid. It prolongs and aggravates wars and often results in high levels of insecurity and violence even after a conflict has ended, including violence against children and gender-based and sexual violence. This hinders post-conflict reconstruction, recovery and reconciliation, as well as human and socio-economic development in the longer term.

What rules related to IHL govern the supply of weapons to a party to armed conflict?

At the global level, the Arms Trade Treaty (ATT) sets common international standards for the regulation of the trade in conventional arms, ammunition, and parts and components. The Treaty's humanitarian aim is to reduce human suffering, and promote responsible action and transparency in the international arms trade (Art 1). The requirements and prohibitions set out in its Articles 6 and 7 seek to prevent serious violations of IHL and other serious violations of international law from being committed with supplied arms. Among other things, the ATT requires that States parties assess the risk of IHL violations being committed or facilitated with transferred arms and to refrain from transfers in certain circumstances (see "When is it prohibited to transfer weapons to a party to an armed conflict?").

Certain regional instruments also restrict arms transfers on humanitarian grounds and require such an assessment. For example, under the EU Common Position 2008/944/CFSP, EU Member States must subject arms export applications to considerations of respect for human rights in the country of final destination as well as respect by that country of international humanitarian law (Criterion 2). Such an assessment is also required to implement Article 5 of the Central African Convention for the Control of Small Arms and Light Weapons, their Ammunition and all Parts and Components that can be used for their Manufacture, Repair and Assembly and Article 6 of the ECOWAS Convention on Small Arms and Light Weapons, Their Ammunition and Other Related Materials.

Treaties on certain types of weapons and other rules of international law impose additional specific prohibition and restrictions on the transfer of weapons to parties to armed conflict (see "When is it prohibited to transfer weapons to a party to an armed conflict?").

Such instruments complement existing limits on arms transfers stemming from each State's obligation to respect and ensure respect for IHL in all circumstances (Article 1 common to the 1949 Geneva Conventions; Article 1 of Additional Protocol 1 to the Geneva Conventions. See also 31st IC, Resolution 2, Action plan, objective 5 (p. 33)). Accordingly, States must refrain from transferring weapons where there is a clear risk that this would contribute to IHL violations, and they must do everything reasonably in their power and take positive steps to ensure respect for IHL by parties to armed conflict.

States' duty to respect and ensure respect for IHL in all circumstances is a key principle underpinning the Arms Trade Treaty (Preamble). States parties must take this into account in their implementation of the ATT and regional arms transfer instruments.

States that supply weapons to a party to an ongoing armed conflict can be considered particularly influential in ensuring respect for IHL owing to their ability to provide or withhold the means by which wars are fought and IHL violations may be committed. In some situations, States may enjoy a position of influence because they import weapons from a party to an armed conflict or for other reasons. States must use this leverage to induce respect for IHL, in particular where there is a foreseeable risk that IHL violations may be committed. Conditioning, restricting or halting transfers of weapons are practical means in the power of arms transferring States to prevent and stop IHL violations. Influential States must take positive action even when the weapons they supply are not implicated in IHL violations.

When is it prohibited to transfer weapons to a party to an armed conflict?

Neither the ATT nor IHL prohibit arms transfers as such to a party to an ongoing armed conflict. However, they prohibit such transfers in certain circumstances, and some States refrain from transfers to parties to ongoing armed conflicts as a matter of national law or policy.

States parties to the ATT are prohibited from authorizing the export, import, transit, trans-shipment and brokering of arms, ammunition and parts and components if they know that these arms or items would be used to commit war crimes or other international crimes (Article 6). States Parties to the ATT are also prohibited from exporting arms or items where there is an overriding risk that these could be used to commit or facilitate a serious violation of IHL or human rights (Article 7).

Similarly, the application of the EU Common Position 2008/944/CFSP, the Central African Convention and the ECOWAS Convention mentioned above can prohibit arms transfers to a party to an ongoing armed conflict in certain circumstances (see: What rules related to IHL govern the supply of weapons to a party to armed conflict?).

In addition, by virtue of their obligation to respect and ensure respect for IHL in all circumstances (Article 1 common to the four 1949 Geneva Conventions), all States are prohibited from transferring weapons to a party to an armed conflict, whether a State or non-state armed group, where there is a clear risk that this would contribute to the commission of IHL violations.

Weapon-specific treaties that prohibit certain types of weapons on humanitarian grounds include an express prohibition to never under any circumstances transfer to anyone, directly or indirectly, the weapons of concern. This is the case for the treaties prohibiting weapons of mass destruction (Treaty on the Prohibition of Nuclear Weapons (Art. 1), Biological Weapons Convention (Art. III), Chemical Weapons Convention (Art. I)) as well as the Anti-Personnel Mine Ban Convention (Art. 1), and the Convention on Cluster Munitions (Art 1). The transfer of these weapons to parties to armed conflicts is therefore prohibited. Similarly the transfer of certain mines is restricted under amended Protocol II (1996) to the Convention on Certain Conventional Weapons (Art 8).

What indicators and sources of information should States take into account in their arms transfer decisions?

In the view of the ICRC, a thorough assessment of the risk that arms, ammunition or parts and components to be transferred could be used to commit or facilitate IHL violations should include an inquiry into:

 - the recipient's past and present record of respect for IHL and human rights
 - the recipient's intentions as expressed through formal commitments, and
 - the recipient's capacity to ensure that the arms or items transferred are used in a manner consistent with IHL and human rights law and are not diverted or transferred to other destinations where they might be used to commit serious violations of IHL or human rights.

Supplying arms to a recipient involved in an on-going armed conflict entails a concrete and present danger that supplied arms, ammunition or parts and components could be used to commit or facilitate IHL violations. For the purposes of the arms transfer risk assessment, isolated incidents of past violations are not necessarily indicative of a recipient's attitude towards IHL or international human rights law. However, any discernible pattern of violations, or any failure by the recipient to take appropriate steps to put an end to and adequately address past violations and to prevent their recurrence should cause serious concern. Evidence of unaddressed recent violations would normally indicate a clear risk.

The final decision should be based on an overall assessment of the situation after considering each indicator separately. Assessments should be based on all available, open- and closed-source information, including diplomatic missions in the recipient State, military-to-military exchanges, reports by UN and other agencies operating in the recipient State, media reports, reports by national human rights bodies, reports by non-governmental organisations, judgments and decisions by international and domestic judicial authorities, and the recipient's military doctrine and instructions.

• Learn more about applying IHL and international human rights law criteria in arms transfer decisions (ICRC, Practical Guide, 2016).

Are arms transfers to non-State armed groups prohibited under IHL?

Neither the ATT nor IHL prohibit arms transfers to non-State armed groups parties to an armed conflict, nor other non-State entities, in general. However, such transfers are prohibited in certain circumstances (See: "When is it prohibited to transfer weapons to a party to an armed conflict?"), and some States refrain from arms transfers to non-state armed groups as a matter of national law or policy.

Other rules of international law, for example the prohibition to intervene in the internal affairs of another State and treaties on certain weapon types may prohibit the transfer of weapons to non-State actors.

An assessment of the risk that transferred weapons could be used to commit or facilitate IHL violations must be conducted regardless of whether the recipient is a State or a non-State entity.

Are weapon transfers in the form of military assistance to allies or trusted partners subject to these rules?

The ATT regulates export, transit, trans-shipment, import and brokering – collectively referred to as 'transfer' (Article 2). The Treaty governs all forms of transfers regardless of whether they entail a commercial exchange or not. Consequently, States parties to the ATT must apply the Treaty's transfer criteria to any government-to-government transfers and military assistance and gifts.

Likewise, the obligation to respect and ensure respect for IHL applies in all circumstances and to all forms of transfers involving a party to an armed conflict, including, notably, to the provision of military assistance.

Exempting arms transfers, including in the form of assistance to a military ally, political partner or State belonging to the same free-trade area or customs union, from a thorough risk assessment runs counter to the requirements of Articles 6 and 7 of the ATT and IHL.

Do these rules apply to the supply of "defensive" weapons and "non-lethal" items?

Conventional weapons and military equipment of any kind can be used to commit or to facilitate violations of IHL and of international human rights law.

States parties to the ATT must apply the prohibitions and requirements of Articles 6 and 7 to all arms and items within the scope of the Treaty (Articles 2, 3 and 4), irrespective of whether these are characterized as 'defensive', 'non-lethal', 'other military equipment' or otherwise in national law or policy.

>All States must subject the supply of any kind of aid or assistance to a party to an armed conflict, including any weapons, munitions and military equipment, to considerations of IHL by virtue of their obligation to respect and ensure respect for IHL in all circumstances (Article 1 common to the 1949 Geneva Conventions).

Whereas the risk of IHL violations associated with the supply and measures available to mitigate that risk may vary in function of the type of material to be provided, a thorough IHL risk assessment needs to be made on a case-by-case basis. Irrespective of how the arms or items are designated, this assessment should include an inquiry into a range of context-sensitive indicators, including the recipient's record of respect for IHL and its intention and capacity to ensure that the supplied material will be used in manner consistent with IHL. (See: "What indicators and sources of information should States take into account in their arms transfer decisions?")

Is the export of weapon parts or components subject to these rules?

States parties to the ATT must apply the prohibitions and requirements of Articles 6 and 7 to parts and components within the scope of the Treaty (Article 4). The ATT does not regulate the re-export of parts and components by a State that is not a party to the ATT, nor the integration of imported parts and components by such a State into a final product and the export of that product. However, a thorough IHL risk assessment under the ATT should include an inquiry into the recipient's intentions and capacity to ensure parts and components are not diverted or transferred to other destinations or recipients where they might be used in violation of IHL.

Under IHL, all States must refrain from transferring parts and components to a party to an armed conflict where there is a clear risk that this would contribute to the commission of IHL violations. Where such a risk exists, States also need to refrain from transferring parts and components to another State or non-State entity if they know or it is reasonably foreseeable that the items would be re-exported to that party or integrated into a weapon to be exported to that party.

States that supply parts and components can be considered particularly influential in ensuring respect for IHL by a party to armed conflict, owing to their ability to provide or withhold the means to repair weapons and keep them in working condition. They must use this leverage to induce respect for IHL, in particular where there is a foreseeable risk that IHL violations may be committed. Conditioning, restricting or halting transfers of parts and components are practical means in the power of arms transferring States to prevent IHL violations.

States parties must take the obligation to respect and ensure respect for IHL into account in their implementation of the ATT and regional arms transfer instruments.

What about practical measures to mitigate the risk of IHL violations?

Possible measures that can support States' compliance with their obligation with regard to the transfer of weapons include conditioning, restricting or halting transfers, as well as confidence-building measures, capacity building programmes and trainings (e.g. in stockpile management or in IHL), post-delivery verification, end-use certificates and assurances.

States should assess cautiously what is realistically achievable in the circumstances to offset the risk of violations. Mitigation measures can only reduce the risk of IHL violations if they are timely, robust and reliable, and if the supplier and recipient have the capacity to effectively implement them in practice and actually do so in good faith. Where a clear risk of IHL violations persists despite the mitigation measures, States must refrain from transferring the weapons.

Are assurances by the arms recipient sufficient to mitigate the risk of IHL violations?

Making the supply of weapons contingent on the recipient providing formal assurances, for example, to use supplied arms or items in compliance with IHL or to avoid using heavy explosive weapons in densely populated areas, can contribute to enhancing the protection of civilians and others not fighting. Such assurances can also serve as an indicator of the recipient's intent to uphold respect for IHL.

Assurances provided by the recipient should, however, be assessed cautiously against its policies and actual practices. Such assurances do not replace the supplier State's obligation to carry out a thorough assessment of any proposed transfer (See: "What indicators and sources of information should States take into account in their arms transfer decisions?"). Where a clear risk of IHL violations persists despite assurances to comply with IHL, States must refrain from transferring the weapons.

Is there an obligation to review previously granted arms transfer licenses?

The ATT 'encourages' reassessment of a previously granted export authorizations if the State party becomes aware of new relevant information (Article 7.7).

In addition, all States have an obligation under IHL to prevent violations of IHL and to refrain from transferring weapons where there is a clear risk that this would contribute to the commission of IHL violations. This requires to continuously monitor how arms trading partners use weapons in practice and to review extant licenses if new information comes to light. If the information indicates a clear or substantial risk of IHL violations, the transfers must be stopped and the authorization amended, suspended or cancelled.

States parties to the ATT must take the obligation to respect and ensure respect for IHL into account in their implementation of the ATT.

May States take national security, the right of self-defence or similar considerations into account in their arms transfer decisions?

In practice, States decisions concerning the supply of weapons to a party to an armed conflict are the result of many factors, including vconsiderations of foreign policy, national security, the recipient State's right of self-defence, or international peace and security.

Such considerations are also reflected in the ATT which aims to reduce human suffering and to contribute to international and regional peace, security and stability (Article 1). States Parties are prohibited from transferring arms or items in violation of their obligations under measures adopted by the UN Security Council under Chapter 7 of the UN Charter, which deals with threats to the peace, acts of aggression and the right of self-defence (Article 6). And States Parties that export weapons must also assess the potential that the arms or items would contribute to or undermine peace and security (Article 7).

None of these considerations allow setting aside or overriding considerations of respect for IHL, including when the arms recipient exercises their right to self-defence. All States that supply arms to a party to armed conflict need to give due consideration to respect for IHL in their arms transfer decisions at all levels, including at the highest political level.

Indeed, it is difficult to see how transferred weapons could ever make a contribution to peace and security in cases where there is a clear risk that they could be used in the commission of IHL violations. (See also: "Are weapon transfers in the form of military assistance to allies or trusted partners subject to these rules?".)

Are arms supplying States considered to be parties to armed conflict?

Under IHL, a State does not become a party to an armed conflict on the sole ground that it supplies weapons or military equipment to a belligerent.

A State supplying arms to a State party to an international armed conflict becomes itself a party to that conflict if it resorts to armed force against another belligerent State, such as when it is effectively involved in military operations against that State.

A State supplying arms to a non-State armed group party to an armed conflict becomes itself a party to the conflict when it equips (with weapons for instance) and finances such group but also coordinates or helps in the general planning of its military activity, thereby exerting overall control over such group.

Learn more about the circumstances in which an arms-supplying State can become a party to an on-going armed conflict involving the recipient State (ICRC Commentary to the Third Geneva Convention, paragraphs 250 and following) or non-State armed group (paragraphs 298, 302 and following, and 440-444).

What are the consequences under international law of transferring weapons in violation of these rules?

Individuals, including government officials and business employees, that transfer arms to a party to an armed conflict can, in certain circumstances, be held criminally responsible for aiding in the commission of war crimes and other serious international crimes committed with supplied arms.

A State party to the ATT may be internationally responsible for a breach of its obligations under the Treaty. All States may be internationally responsible for a breach of their obligation to respect and ensure respect for IHL in all circumstances (Article 12, ILC ASR).

In addition, a State that supplies weapons to a party to an armed conflict may, under certain conditions, be internationally responsible for aiding or assisting in the commission of an internationally wrongful act by that party (Art 16, ILC ASR), or in maintaining a situation of serious breach of an obligation arising under a peremptory norm of general international law (Art 41.2, ILC ASR).

What is the responsibility of defence companies that supply arms to a party to an armed conflict?

The ATT does not apply directly to defence companies or other business entities, their employees or representatives. However, there are a number of reasons why private business entities need to carefully assess and effectively mitigate the risk of their activities causing or contributing to violations of IHL or human rights.

1. Non-compliance by a private business with the national laws and regulations that each State Party is required by the ATT to adopt and enforce (Article 14), such as a failure to conform with the terms of an arms transfer license, exposes the business to criminal, civil or administrative enforcement measures.

2. States have obligations under international humanitarian law to ensure that private individuals and entities within their jurisdiction respect IHL. The national laws and other measures States adopt to meet these obligations frequently provide for criminal or civil liability of private individuals and corporations.

3. Individuals who act on behalf of a private business can be directly bound by IHL where their activities are sufficiently connected with an armed conflict. Providing weapons to a party to an armed conflict can result in criminal liability under international law for the individuals involved if that party uses the weapons to commit war crimes or other international crimes. In addition to reputational risks to the business entity, national laws frequently include general provisions making employers, including corporations, civilly or criminally liable for wrongful acts of their employees.

4. Business entities have a general corporate responsibility to respect human rights as reflected for instance in the UN Guiding Principles on Business and Human Rights.