July 2023

This note is intended to accompany the data and findings following our publication of all alleged US actions in Yemen during Obama’s first term 2009-Jan 2013. These are all published as assessments available in our archive.

This is the first phase of work, with the second phase covering Obama’s second term, between 2013-17, still undergoing assessment and investigation.

Accompanying methodology notes will be made available on our website upon publication.

Dataset overview

An incident

Airwars uses an incident-based approach to document alleged US strikes in Yemen: each incident is defined as a moment in time and space where sources alleged US involvement in a drone or airstrike that led to the fatality or injury of civilians or militants.

We have also coded for damage to civilian infrastructure in cases where alleged US strikes were also reported to have caused casualties and injuries. Our definition of ‘infrastructure’ is evolving, but to date accounts for any mention of the following terms by sources: hospital, school, agriculture marketplaces, gas facility, power station, water station, religious place.

Where the exact time of an incident is unknown, deaths and injuries may be aggregated under one event until more information comes to light. Each incident is geolocated to the highest possible degree of accuracy by trained geolocation teams, though in general for this dataset the geolocation process in Yemen has been challenged by a lack of available incident related imagery.

Where locations cannot be identified, incidents will be aggregated until more information is known. All incidents are considered ‘live’ in our archive, and can be updated and changed to account for evolving information.

The Bureau of Investigative Journalism: preserving the original archive
Airwars made extensive use and citation of data collected on US actions in Yemen by The Bureau of Investigative Journalism (TBIJ), who handed over their dataset and research to Airwars when their drone monitoring programme came to a close.

TBIJ’s research also includes incidents where no fatalities were recorded, and focused predominantly on English-language media. Though we have not otherwise investigated strikes without casualty allegations, these incidents have nevertheless been kept within the Airwars archive to preserve the original record, and include the following standard statement: “This incident was identified by the Bureau of Investigative Journalism and has been included in Airwars’ database even though no casualties are mentioned.”

Source identification

We assessed all known open source claims of US strikes in Yemen since 2009 that resulted in casualties. This includes covering all open source allegations of death or injury of ‘civilian non-combatants’ or ‘militants’.

Sources were identified by our trained team of Yemen researchers, using an incident-based method to develop a continuously evolving list of sources for monitoring and investigating allegations of US strikes. Out of more than 2,600 sources archived, 35% are Arabic language sources, and 65% are English language sources. These sources originate from Twitter (approx 40%), local and international media/NGos (approx 58%) as well as Facebook.

We included any and all information relevant to a single incident of US strikes, whether this includes mention of civilian or militant harm or not, and regardless of the affiliation of the source.

We have additionally conducted a data mapping exercise coordinating with other civil society and documentation groups in order to cross-check our database with existing and similar datasets.

All information is assessed, written up and archived within each assessment in order to allow the user of the dataset to conduct further investigation if needed.

‘Strike’ terminology

The term ‘strike’ is used throughout this document and in our analysis to mean a kinetic action; each assessment further classifies this action depending on the level of detail provided by sources relating to the incident – for example, a naval bombardment, airstrike or drone strike.

Strike status

No US strikes have been officially declared by either CENTCOM or by the CIA between 2002 and 2017.

Declared: Between 2009-Jan 2013, due to the nature of both CIA and US military involvement in Yemen, and the lack of official acknowledgment by the CIA for their involvement, in lieu of public reporting on CIA actions, Airwars graded events as ‘declared’ strikes due to either:

1. A US government official statement acknowledging responsibility – for example, Attorney General Eric Holder
2. Comments made by anonymous US government sources to major media outlets (ABC News, Fox News, Wall Street Journal, Los Angeles, Washington Post, Al Arabiya, Long War Journal)
3. Reference in leaked diplomatic cables regarding US involvement in specific strikes released by Wikileaks. The cables revealed that the Obama administration was instructing the Yemeni government to take credit for strikes carried out by the US military.

Likely: The likely strike classification applies to incidents in which all of the sources reported on the incident attributed the strikes to US forces. In cases where all of the sources attribute the strike to the US military, and Yemeni officials have acknowledged to the media that the strike was carried out by the US, the strike is qualified as “likely” as well.

Contested: The contested strike classification includes incidents in which attribution of the strike to the US military was not agreed upon by all sources reporting on the incident.

This category has also been used to capture incidents using a broad inclusion criteria that reflects on the likelihood of US involvement, even if it was not explicitly mentioned by the sources. This includes cases of precision strikes on a moving target during night time or drone strikes, which fit a wider likely pattern of US military engagement as well as the documented limitations of the Yemeni military to carry out these types of strikes. We have chosen this broad approach given the high level of secrecy around US actions, as well as findings from investigators and in Wikileaks around the Obama administration explicitly instructing the Yemeni government to take credit for US strikes.

Each case should be treated with caution and read closely in order to understand this designation, which is outlined clearly within each assessment.

Single source claims: only one source was found with an allegation of harm from US forces.