In October 2016, warplanes from a Saudi-led coalition bombed a community hall in Yemen’s capital, Sanaa, where mourners had gathered for a funeral, killing at least 140 people and wounding hundreds. International condemnation was swift after that attack—the deadliest since Saudi Arabia and several of its allies launched a war against Houthi rebels in Yemen in March 2015. Within days, United Nations Secretary General Ban Ki-moon called for an international investigation into whether the attack constituted a war crime. “Aerial attacks by the Saudi-led coalition have already caused immense carnage and destroyed much of the country’s medical facilities and other vital civilian infrastructure,” Ban said, adding, “Parties cannot hide behind the fog of this war. A man-made catastrophe is unfolding before our eyes.”
The Saudi coalition, which includes the United Arab Emirates, was not the only party potentially implicated in war crimes. The attack on the funeral hall, which targeted services for the father of a prominent Houthi leader, renewed international attention on the United States and its deepening involvement in the Saudi-led war. President Barack Obama’s administration pledged to conduct “an immediate review” of its logistical support for the Saudi coalition. (In addition to providing intelligence assistance and refueling support for warplanes, Washington had rushed billions of dollars in missiles, bombs, and spare parts to help the Saudi air force continue its bombing campaign.) The National Security Council’s then-spokesman, Ned Price, said the administration was “deeply disturbed” by the attack, and was prepared to adjust its level of support. He added, “US security cooperation with Saudi Arabia is not a blank check.” Human Rights Watch reviewed footage and photos after the attack and found that the Saudi coalition used at least one US-made 500-pound laser-guided bomb. The group deemed it “an apparent war crime.”
Even before the attack on the funeral hall, some US officials were worried that American support to the Saudis—especially weapons transfers, assistance in identifying targets, and midair refueling of Saudi and allied aircraft—would make Washington a co-belligerent in the war under international law. That means the United States could be implicated in war crimes and American personnel could, in theory, be exposed to international prosecution. By late 2015, Reuters reported, administration officials had debated internally for months about whether to go ahead with arms sales to Saudi Arabia, which was becoming America’s largest weapons customer, in light of the rising civilian death toll in Yemen.
Documents obtained by Reuters under the Freedom of Information Act showed that US officials were especially worried about a 2012 ruling from an international tribunal at The Hague that convicted Charles Taylor, Liberia’s former president. He was found guilty of aiding and abetting war crimes committed by rebels in neighboring Sierra Leone during its civil war in the 1990s, and sentenced to 50 years in prison. The ruling built on precedents set by the Yugoslavia war crimes tribunal, which found that the accused can be guilty of “aiding and abetting” if he provided “practical assistance, encouragement, or moral support which had a substantial effect on the perpetration of a crime.” The court found that prosecutors do not have to prove that a defendant had direct control over the perpetrators, or participated in a specific crime. US government lawyers worried that similar legal reasoning could be used to prosecute American officials who continue to provide weapons and military assistance to the Saudi-led coalition, despite mounting evidence that it was committing war crimes.