As part of a series of articles on international law and the war in Yemen, Just Security recently published a piece by several legal scholars regarding the War Crimes Act and the US federal statute on aiding and abetting. The authors conclude that US government personnel face limited legal risk of prosecution for aiding and abetting violations by the Saudi-led coalition under the War Crimes Act. It would likely be difficult to establish the requisite mens rea--proof of intent--due to the fact that US military support for the Saudi-led coalition is ostensibly accompanied by training on law-of-war compliance and civilian protection. This is debatable, however, because some observers argue that the deep, systemic problems in the Saudi military render it incapable of carrying out independent air operations without violating international humanitarian law principles. The applicability of these federal laws is important because, although other international venues exist for the prosecution of war crimes, the US generally will not allow foreign or international courts to try US officials or military personnel. The article concludes that another case, the participation of US personnel in the torture and abuse of detainees held by the UAE at sites in southern Yemen, would be easier to prosecute. Those US personnel face greater potential liability for violating the War Crimes Act by aiding and abetting UAE crimes.

The federal statute for aiding and abetting (18 U.S.C. § 2) states:

(a) Whoever commits an offense against the United States or aids, abets, counsels, commands, induces or procures its commission, is punishable as a principal.

(b) Whoever willfully causes an act to be done which if directly performed by him or another would be an offense against the United States, is punishable as a principal.

According to the UN Panel of Experts as well as several leading NGOs, the Saudi-led coalition has engaged in “intentional targeting of civilians” in Yemen. These allegations, if substantiated in federal court, would amount to war crimes under the standard prescribed by the War Crimes Act as a “grave breach” of Common Article 3.

US officials might be found responsible for aiding and abetting these war crimes if the prosecution were able to demonstrate that without the support of the United States, the Saudi-led coalition would not have carried out the attacks. This argument could be made with available evidence that 1) the Saudi-led coalition is reliant on US weapons transfers to continue its operations in Yemen and 2) the Saudi-led coalition depends on mid-air refueling by US jets.

There have also been reports that the US may have been complicit in the torture of detainees by UAE forces. If reports of US forces’ participation in acts of torture are substantiated, the article finds, they would constitute aiding and abetting because they would be a violation of the War Crimes Act if US officials had committed the acts directly. According to the article, there is a strong causality argument that could be made to reveal that if the US has provided questions to UAE interrogators and detainees were subjected to torture to obtain answers to those questions, the US officials could be said to have caused that torture. Additionally, if US forces were present at interrogations involving torture, the court could infer meaningful intent.

It might be difficult to find US officials responsible for aiding and abetting war crimes resulting from Saudi-led coalition airstrikes. The mens rea provision requires prosecution to prove that US officials intended to support the murder of civilians by the Saudi-led coalition. This would be difficult to prove because the US claims to have taken steps to reduce the likelihood of IHL violations. However, US involvement in UAE interrogations involving torture might constitute aiding and abetting war crimes, and would be easier to prove in court, given the requisite provisions.