Four Democratic senators are investigating whether the Pentagon adequately protected US personnel before an Iranian drone attack killed six service members in Kuwait. The inquiry matters because it raises questions about force protection, official accounts of the strike and accountability within the Defence Department during the conflict with Iran.

Sens. Elizabeth Warren, Richard Blumenthal, Kirsten Gillibrand and Mark Kelly asked Defence Secretary Pete Hegseth for information on risk assessments, known threats and responsibility for protecting the Shuaiba Port post. The March 1 attack also injured about 20 people; the senators said the site had barriers but lacked a system to intercept drones, and requested a response by 11 May.