Are the US and UK parties to the Saudi-led armed conflict against the Houthis in Yemen?

A series of messages on just security focused on the rules that apply to US and UK support for Saudi-led coalition military operations against Houthi rebels in Yemen. A key question is whether supporting states, such as the United States and the United Kingdom, avoid becoming a “party” to the armed conflict (and therefore being bound by international humanitarian law) by providing assistance who stops before engaging in direct combat. What kind of support will make an assisting state a party to this conflict?

I. Current scope of US and UK support

we assistance to the Saudi-led coalition has included the provision of weapons, intelligence sharing, targeting assistance and in-flight refueling of jet aircraft. In March last year, the spokesperson for the NSC declared that in support of Gulf Cooperation Council actions against Houthi violence, “President Obama has authorized the provision of logistical and intelligence support to GCC-led military operations. Although US forces are not taking direct military action in Yemen to support this effort, we are establishing a joint planning cell with Saudi Arabia to coordinate US military and intelligence support.

In the UK, a joint report released last week by the House of Commons Business, Innovation and Skills and International Development Committees and another report by the Foreign Affairs Committee both state: “The UK support for Saudi Arabia’s military intervention in Yemen has been significant as it remains short of engaging in actual combat. … Our involvement ranges from supplying aircraft and bombs for airstrikes to British personnel in the Saudi Joint Planning Cell and Air Operations Centre.

This type of support is not exclusive to the armed conflict in Yemen. For example, we witnessed similar assistance when the United States provided air-to-air refueling and transported allied soldiers from African countries to support France in the armed conflict in Mali in 2013.

II. Approaches to determining whether a State is party to a pre-existing non-international armed conflict (NIAC)

In a context such as this particular conflict in Yemen, in which the United States and the United Kingdom are not directly engaged in combat, the traditional two-pronged test for declaring them parties to a non-international armed conflict (some intensity of fighting and a level of non-state armed group) will not be encountered as there are no direct hostilities between them and the Houthis. However, as I have explained in previous articles on just security in 2015 (see here, and here), two approaches can help determine, from the facts, whether a country has become a party to a pre-existing NIAC for the purposes of applying international humanitarian law (IHL): (1) the “support-based approach”; and (2) the concept of “co-belligerency” under the international law of neutrality.

The “support-based approach” is particularly relevant because “modern armed conflicts are increasingly fought by coalitions and alliances of several States and/or international organizations whose involvement in hostilities may vary…”. In this approach, a State will be considered a party to a pre-existing NIAC when the following four conditions are met:

  1. There is a Pre-existing NIC in progress on the territory where the support forces intervene;
  2. Intervention forces take action related to the conduct of hostilities in the context of the pre-existing conflict;
  3. The military operations of the intervention forces take place in Support a party to that pre-existing conflict;
  4. The intervention in question is undertaken under a official decision by the country in question to support a party involved in the pre-existing conflict.

Ferraro explains that indirect forms of support such as the supply of arms or financial support would not meet the criterion. Instead, there must be a “close link” between the action of supporting forces and the damage caused to the enemy by specific military operations. For example, “transporting the armed forces of the supported state to the front line or providing aircraft for refuel fighter jets involved in state-supported air operationswould make the intervening State a party to the armed conflict. With regard to the third criterion of support, Ferraro adds that it must be obvious that “two or more States or international organizations are pooling or assembling military resources in order to fight a common enemy. … Set up ad hoc joint military mechanisms or sign an agreement to strengthen cooperation between the forces[…]and the territorial state’s armed forces with respect to the pre-existing conflict would certainly tend to suggest some form of support and therefore the existence of the requisite connection. The fourth criterion simply aims to ensure that the support is intentional rather than resulting from an error or an act beyond the authority of the intervention forces.

The concept of co-belligerence under the international law of neutrality (designed to apply in international armed conflicts) could also serve as a source of guidance in determining whether a supporting state is party to a pre-existing NIAC. Under the law of neutrality, a state becomes a co-belligerent when, in association, cooperation, assistance or common cause with another belligerent, it participates in hostilities to a significant extent or systematically or substantially violates its duties of neutrality, impartiality and non-participation in the conflict. Examples of violations of a state’s neutrality include supplying war material, committing its own military forces, supplying military advisers to a party to the armed conflict, or supplying or transmitting military intelligence on behalf of of a belligerent. Interestingly, the United States borrowed the concept of co-belligerence determine whether the armed groups constitute forces associated with Al-Qaeda for purposes of applying the 2001 Congressional authorization to use force. Geoffrey Corn has Explain to the Senate Armed Services Committee that “the focus on ideology, tactics, and clues of connection between high-level group leaders therefore appears to emphasize both logical and legitimate intelligence indicators of which offshoots of al-Qaeda fall into the category of co-belligerents.”

III. An obligation to uphold IHL

If becoming a party to the conflict is what triggers the application of IHL, it is important to remember that even no-parties to an armed conflict have general obligations with regard to their support activities. Under Article 1 common to the Geneva Conventions of 1949 and their Additional Protocol I, States must to assure respect for IHL by other parties to an armed conflict. under custom to reign, they “shall not encourage violations of international humanitarian law by parties to an armed conflict. They must exert their influence, to the extent possible, to put an end to violations of international humanitarian law. It was describe as an obligation to due diligence under which “a State having close political, economic and/or military links (for example, through the equipping and training of armed forces or the joint planning of operations) with one of the belligerents has a greater obligation strong to ensure respect for IHL by its ally. …” This obligation is particularly relevant in the Yemeni context today in light of the influence that contributor countries like the United States (which have challenged the obligation in law but seek to promote membership as a policy ) and the UK may have on Saudi Arabia in particular.

In fact, the IHL provisions of the Arms Trade Treaty (ATT) can be seen as a derivative of this common obligation in Article 1. In its principles section, the ATT reiterates the obligation of all States to ensure compliance with IHL and, in the body of the he instrument translates this into two obligations: It prohibits arms transfers if the transferring State knows that the arms would be used in the commission of certain war crimes; in the absence of such knowledge, a State must carry out a risk assessment and refrain from exporting weapons if it finds a major risk that the weapons could be used to commit or facilitate a serious violation of IHL. (A similar and perhaps even stricter obligation exists in the EU Common position on arms export controls.) The ICRC has just published an update guide to carry out such risk assessments in arms transfer decisions. Regarding the point where the risk of violations requires a refusal to transfer, it states that “any discernible pattern of violations, or any failure of the recipient to take appropriate measures to end the violations and prevent their recurrence, should cause serious concern.”

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Reports of civilian casualties and general suffering in Yemen due to the conflict between the Saudi-led coalition and the Houthis are certainly not lacking. If the United States, the United Kingdom and perhaps others contribute to the conflict in such a way that they are parties to it even without engaging in direct combat, then they are also bound by IHL. For these parties, IHL to reign Requiring that all possible precautions be taken to avoid and minimize accidental loss of civilian life, injury to civilians and damage to civilian objects is particularly relevant. Moreover, whether or not the United States, the United Kingdom or other countries which support them are considered parties to the armed conflict alongside the coalition, their influence is certainly evident, as is their corollary duty to guarantee respect for IHL.

* The opinions expressed here are those of the author and do not necessarily reflect the views of the United Nations.