The United States is reportedly finalizing arms deals with Saudi Arabia and Bahrain in a reversal of President Obama’s blockage of certain weapons deals during the final months of his administration. The weapons package includes $300 million worth of precision-guided weapons. Human rights groups are reiterating concerns that these arms deals contribute to human rights abuses in Yemen, perpetrated in part by the Saudi government.

A rebel Shia group, the Houthis, overtook the Yemeni capital of Sanaa in March 2014 and successfully ousted Yemen’s existing government in January 2015. A Saudi-led coalition responded with a bombing campaign against the Houthis and allied forces. Now, two years into this civil war, 10,000 people have been killed, and Human Rights Watch (HRW) reports that the Saudi bombing campaign has targeted schools, hospitals, and other essential structures. Evidence collected by HRW also suggests some of these bombings were carried out with weapons provided by the United States.

Thus, some raise questions of whether the United States can be considered complicit in the violations of international law occurring in Yemen, particularly considering that the United States has provided both intelligence and plane fuel to the Saudi military.  In addition, parties to the conflict have blocked relief supplies from reaching civilians, and as of February 2017, the UN has declared that Yemen is on the brink of famine. A former UN official and chair of the Norwegian Refugee Council, Jan Egeland, provided sobering commentary, stating “if bombs don’t kill you, a slow and painful death by starvation is now an increasing threat.”

International law regulating whether a State can be held to be complicit in war crimes due to the sale of weapons is still developing. Article 25 of the Rome Statute, to which the United States is a signatory, assigns criminal liability to individuals for aiding, abetting, or assisting in the commission of a war crime, including providing weapons for the commission of such a crime. Under Article 8, an actor commits a war crime if it “intentionally direct[s] attacks against the civilian population” or “buildings dedicated to religion, education, art, science or charitable purposes, historic monuments, hospitals, and places where the sick and wounded are collected.” If Saudi Arabia is committing war crimes, the International Criminal Court (ICC) has jurisdiction to decide its criminal liability. The Rome Statute is unclear on whether states can be held similarly liable as compared to individuals. Additionally, the United States is not a party to the ICC.

In 2001, the International Law Commission—established by the General Assembly of the United Nations—codified the Articles of Responsibility of States for Internationally Wrongful Acts, which states that “a State which aids or assists another State in the commission of an internationally wrongful act by the latter is internationally responsible for doing so if: (a) that State does so with knowledge of the circumstances of the internationally wrongful act and (b) the act would be internationally wrongful if committed by that State.” The Articles are only persuasive authority, but they may lend support to the idea that States have a legal obligation (i.e. opinio juris) to refrain from aiding or abetting in war crimes. However, States would need to act consistently within these legal obligations before the Articles could become binding customary law.

The United States should cease arms deals with Saudi Arabia to avoid complicity with war crimes and crimes against humanity. A moral obligation, if not a binding legal obligation, should guide President Trump’s future policy regarding weapons deals.