In the past four months, the United States and the United Kingdom have conducted repeated airstrikes against the Yemen-based Houthi militia, following a series of Houthi attacks on vessels in the Red Sea. While the U.S. and U.K. government have repeated assurances that they are taking “great care” to avoid civilian harm, allegations have emerged of both deaths and injuries to Yemeni civilians from the campaign. Beyond direct harm, airstrikes are also alleged to have taken place near infrastructure which is vital to sustaining civilian life, risking the safety of civilians in local communities for years to come.

The strikes in Yemen are occurring against the backdrop of significant policy efforts within the United States and United Kingdom to address civilian harm resulting from military operations overseas. In its Department of Defense Instruction (DOD-I) on Civilian Harm Response and Mitigation (CHMR), for example, the U.S. Department of Defense (DOD) emphasizes that the importance of effective mitigation is:

“based on strategic, moral, policy, operational, legal, and  other considerations […] CHMR supports U.S. national security interests,  including by furthering strategic objectives to achieve long-term strategic success, enhancing the  effectiveness and legitimacy of military operations, and demonstrating moral leadership.”

Similarly, in signing on to the political declaration on the use of explosive weapons in populated areas (EWIPA), the United Kingdom and the United States both endorsed the statements:

“We recognise the importance of efforts to record and track civilian casualties, and the use of all practicable measures to ensure appropriate data collection […] We stress the imperative of addressing the short and long-term humanitarian consequences resulting from armed conflict involving the use of explosive weapons in populated areas.”

Yet there is little detail available on what this has meant in practice in Yemen — and it remains unclear how the United States and United Kingdom will respond to allegations of civilian harm as they emerge, especially as the two states have drastically different approaches to the issue.

Direct and Indirect Harm to Civilians 

Several civilians have been reported killed and injured in U.S. and U.K. airstrikes conducted in Yemen to date. In one strike, two civilians were reportedly injured in an alleged U.S.-U.K. airstrike in what a witness described as a “densely populated residential neighborhood” in the capital Sana’a. In another case, an allegation of harm claimed that a man and a child were killed while fishing on Feb. 29. Some sources blamed a Houthi drone for the incident, while others — including other fishermen present during the strike — blamed U.S. warplanes.

Additionally, U.S.-U.K.forces appear to have targeted Houthi assets in or near civilian infrastructure on which civilian life depends. Notably, infrastructure in the city of Hudaydah has been struck by alleged joint U.S.-U.K. strikes on multiple occasions.

While these strikes have not directly targeted Hudaydah Port, which plays a vital role in receiving aid for millions of Yemeni civilians, strikes near the facility introduce risks to the effective running of the port’s operations. There has been no public statement from either military on what measures were taken to mitigate such indirect risks to civilians from their airstrikes. In fact, when asked in a parliamentary question whether an assessment had been made of the risk to civilians from a closure of Hudaydah Port, a U.K. Parliamentary Under-Secretary of the Foreign and Commonwealth Overseas Development Department simply emphasized the importance of Hudaydah Port to Yemeni civilians, failing to clarify whether considerations had been made of the risk to civilians from U.K. and U.S. strikes.

Commitments on Working with Partners 

Both the United States and the United Kingdom have committed to investigate allegations of civilian harm from their strikes; they should now make it a priority to do so. If the allegations are found to be plausible, the responsible state(s) should acknowledge this publicly and aim to make amends to those left behind.

Beyond revealing the harm to civilians emerging from Operation Prosperity Guardian, recent strikes also highlight discrepancies between the United States and United Kingdom in how they approach several key elements of CHMR, including tracking and investigating harm. This is particularly problematic for the United States, which has recently made repeated commitments to ensure that coalition partners operate according to the high CHMR standard. The DOD-I, for instance, emphasizes that the United States will:

“…conduct civilian harm baseline assessments of allies and partners (CBAPs). CBAPs will address the ability, willingness, norms, and practices of allies and partners to mitigate and respond to civilian harm, and will incorporate consideration of the ally or partner’s record with regard to CHMR, and their programs, mechanisms, and other efforts to implement the law of war and its protections for civilians and civilian objects.”

Airwars has submitted allegations of civilian harm to CENTCOM per their standard process, and has received confirmation that these allegations are being reviewed by CENTCOM’s Civilian Harm Assessment Cell. By contrast, it is unclear to civil society groups who have worked on this for years what — if any — formal system the United Kingdom has to assess civilian harm from its strikes. During a recent tribunal, in which Airwars challenged the U.K. Ministry of Defence’s lack of transparency on a civilian harm incident, the senior official acting as witness proved unaware of a standard of proof the United Kingdom used when investigating allegations of civilian harm, whether written procedure governed investigations, and whether the United Kingdom  tracks allegations at a systemic level. The U.K. government noted in its strike reporting: “In planning the strikes, as is normal practice with such RAF operations, the greatest possible care was taken to minimize any risk of civilian casualties.” What those steps are, however, has never been presented as a matter of public record.

While it is unclear what CHMR systems the United Kingdom has in place, they are likely not the same systems as those used by the United States. The United Kingdom and the United States do not, for instance, appear to share a methodology when it comes to the practice of assessing and responding to civilian harm — and have in fact reached different conclusions on the same incidents on multiple occasions. The single civilian casualty that the United Kingdom had admitted from its substantive contribution to the anti-ISIS coalition in Iraq and Syria for instance, was not recognized by the DOD-led team that conducted investigations for the coalition. Conversely, while the coalition finds civilian harm from a British strike in Mosul in November 2016 “credible,” the United Kingdom denies that any harm to civilians occurred as a result of the strike.

What’s Next 

As with all policy commitments, the impact of the DOD-I, CHMR-AP, and EWIPA declaration — documents which have the potential to drastically improve CHMR efforts on the whole — depend on the quality of implementation. And the improvements they promise are urgently needed; the documents build on the lessons of two decades of warfare, which have left thousands of civilians injured or killed, often with little accountability.

Yet rather than being an example of the changes to come from these, Operation Prosperity Guardian and Operation Poseidon Archer have highlighted gaps between rhetoric and reality on considerations of reverberating effects in the targeting process, as well as concerns about U.S. commitments to ensure allies share key CHMR methodologies. As it stands, it is unclear whether the new coalition has a designated system for CHMR, how they are tracking and investigating allegations of civilian harm, and what avenues of amends those injured can rely on. As more civilian harm allegations emerge, it is becoming increasingly urgent for both the United States and the United Kingdom to address these concerns in order to fulfill their own policy commitments.

IMAGE: A Yemeni man browsing the news on his laptop screen that broadcasts U.S.-U.K. warships amid news spread relating to the attack on the Zografia ship in the Red Sea, on January 16, 2024, at his home in Sana’a, Yemen. (Photo by Mohammed Hamoud/Getty Images)