Direct transfer record
The documented M933-series link to the 2014 Yemen Civil War is a proposed U.S. export to Saudi Arabia rather than public proof of a named firing incident in Yemen. S.J.Res.45, passed by the Senate on 20 June 2019, identified a proposed export of 15,000 120 mm M933A1 mortar bombs to Saudi Arabia for end use by the Royal Land Forces of the Kingdom of Saudi Arabia.
Security Assistance Monitor treated the M933A1 mortar-bomb case as one of the expedited U.S. arms transfers to Saudi Arabia and the United Arab Emirates during the Yemen war, placing it in the same policy context as U.S. support to Saudi-led coalition forces.
Sources: GovInfo S.J.Res.45 M933A1 Saudi transfer, Security Assistance Monitor Saudi UAE Yemen sales factsheet
Timeline
The public chronology starts with the 2019 congressional review of emergency arms-transfer cases. The Senate bill text cites Executive Communication 1416, submitted under the Arms Export Control Act and published in the Congressional Record on 3 June 2019, as the underlying notification for the 15,000-round M933A1 export.
The same resolution passed the Senate on 20 June 2019. The cited records do not establish a delivery date, unit-level receipt inside Saudi Arabia, cross-border movement into Yemen, or a documented firing of M933A1 rounds during the conflict.
Sources: GovInfo S.J.Res.45 M933A1 Saudi transfer, Congressional Record June 2019 arms-sale resolutions
Role and evidence boundary
In catalog terms, the M933A1 appears in the Yemen conflict as heavy mortar ammunition in a Saudi-led coalition transfer context. General Dynamics Ordnance and Tactical Systems describes the M933A1 as a 120 mm high-explosive cartridge for M120 and M121 mortar systems, using an M783 point-detonating/delay fuze and intended for personnel, bunker, and light materiel targets.
CNA's 2019 study of U.S. security assistance in Yemen describes Saudi Arabia's March 2015 formation of a coalition after President Hadi requested Gulf Cooperation Council assistance, and it notes U.S. support to Saudi Arabia and coalition partners during the campaign. That context supports the side assignment to Yemeni government and Saudi-led coalition forces, while the M933A1-specific claim remains limited to the proposed export record and the Security Assistance Monitor Yemen-sales grouping.
Sources: 120MM M933A1 HE, CNA Learning from Yemen, Security Assistance Monitor Saudi UAE Yemen sales factsheet