[Just Security is publishing a series of articles by experts discussing the major UN report on the Yemen War. This is the third article in the series.]

As family tradition had it, 70-year-old Abdelqawi al-Kindi and his 60-year-old wife Hayat had gathered with their extended family for the weekly Friday lunch in their home in Warzan, a small village in the governorate of Ta’iz, Yemen. As his children and grandchildren flocked around them, little did they know that it would be the last family lunch they would have together. On that day, 28 June, an air strike by the Saudi and Emirati-led Coalition struck their living room as they all sat together, killing six of their family members, including Abdelqawi, Hayat, their two sons, and their two grandchildren, both of whom were under the age of seven.

When we spoke to a family member, he described how the strike had ripped all their bodies apart. They had gathered the remaining limbs and severed parts in blankets and buried them on the same day. Graphic videos of the aftermath showed parts covered with blankets and grieving and distraught family members sobbing.

Based on our documentation from the past five years, the air strike on the al-Kindi house must not be considered an anomaly, or a digression from the Coalition’s conduct in Yemen, since the start of the air campaign in March of 2015. Indiscriminate and disproportionate air strikes by the Saudi and Emirati-led Coalition have killed and injured civilians and displaced millions of them. Since coalition air strikes began, Amnesty International has visited and investigated dozens of air strike sites in eight governorates. We have repeatedly found and examined remnants of bombs manufactured in the United States. Other reputable NGOs, such as Mwatana, have dug up similar evidence. Now, the recent Report of the Group of Eminent International and Regional Experts on Yemen, established by the UN Human Rights Council, also confirms a wide range of violations of human rights and international humanitarian law by all parties to the conflict in Yemen, including serious violations that may amount to war crimes.

Why should this matter for U.S. lawmakers? Because, simply put, along with allies including the United Kingdom (UK), and France, the United States arms, trains, refuels (until 2018 at least) and shares intelligence with Coalition forces. Just this spring, President Trump, citing new military tensions with Iran, used an “emergency” loophole in U.S. arms control law to bypass Congress to complete the sale of more than eight billion dollars in weapons to the Kingdom of Saudi Arabia, the United Arab Emirates (UAE) and Jordan. The move circumvented U.S. law that gives Congress power to review weapons sales.

By knowingly supplying the means by which the Saudi and Emirati-led Coalition repeatedly violates international human rights and international humanitarian law – including the crucial rules of proportionality, distinction, and precautions in attack – the U.S. shares responsibility for these violations.

The report of the Group of Eminent Experts has been clear about exactly this issue in its conclusions based on the investigation of emblematic airstrikes carried out by the Saudi and Emirati-led coalition: such repeated patterns raise “a serious doubt about whether the targeting process adopted by the coalition complied with these fundamental principles of international humanitarian law.”

Most importantly for the U.S. context, the report raises questions of responsibility related to third states, including the United States (others include the UK, France, and Iran), who directly or indirectly support parties to the conflict through the provision of arms. Specifically, the Group concludes that all arms transfers to members of the Saudi and Emirati-led Coalition, even by States that are not party to the Arms Trade Treaty, may not only trigger State responsibility in the sense that they may violate the obligation of States to cooperate to bring to an end any serious breach of international law, but also could amount to knowingly aiding or assisting members of the Saudi and Emirati-led Coalition in the commission of internationally wrongful acts.

Following the Group of Experts’ reporting, the U.S. government cannot bury its head in the sand and pretend that it does not know of the risks associated with arms transfers to parties to this conflict. Despite copious evidence of coalition air strikes that have violated international humanitarian law by indiscriminately or disproportionately killing and injuring Yemeni civilians and the conclusions about responsibility of arms supplying states by the Group of Experts, the United States continues to supply arms to Saudi Arabia and the UAE.

But something is changing in Washington, DC. Congress has taken a series of votes to rebuke the White House for writing blank checks to support oppression and human rights violations across the region, particularly in Yemen. The electorate has come together to try to hold Saudi Arabia and the UAE accountable for a weapons proliferation crisis, and repeated violations of international human rights and humanitarian law from coalition airstrikes.

The shift in Washington may come too late for the families who have already lost their loves ones or the millions on the brink of famine in Yemen. Nor will this shift be entirely successful unless there is a change in President Trump’s consistent support for the Saudi and Emirati-led coalition’s involvement in Yemen, demonstrated by his repeated vetoes of congressional action to end the carnage, or in leading Senate Republicans who provide cover for him. But there is one thing that can be said of the Group of Experts’ report, and the work being done to highlight the crisis in Yemen: that the U.S (and its allies) have helped create the greatest humanitarian disaster of our time and they have a duty and ability to help end it, starting by immediately ending their arms sales to the Saudi and Emirati-led coalition. Providing humanitarian aid is not enough. Stopping arms sales will help end this madness, and the time to act is now.