Report 20210227A


February 27, 2021


Joe Biden (Current Term)



Was 4(a)(1) Triggered? (Hostilities/Imminent Hostilities)

Yes, described in/inferred from report

Was 4(a)(2) Triggered? (Combat- Equipped Introduction)

No, as described in/inferred from report

Was 4(a)(3) Triggered? (Substantial Enlargement)

No, as described in/inferred from report

Joint/Coalition Mission


Article 51 Report to UN


Details: S/2021/202


Respond to threat

Details: "In response, I directed this military action to protect and defend our personnel and our partners against these attacks and future such attacks."

Domestic Legal Authority

Constitution (Art. II)

Details: "I directed this military action consistent with my responsibility to protect United States citizens both at home and abroad and in furtherance of United States national security and foreign policy interests, pursuant to my constitutional authority to conduct United States foreign relations and as Commander in Chief and Chief Executive."

Claimed International Legal Basis


Details: "The United States took this action pursuant to the United States’ inherent right of self-defense as reflected in Article 51 of the United Nations Charter"; "The United States always stands ready to take necessary and proportionate action in self-defense, including when, as is the case here, the government of the state where the threat is located is unwilling or unable to prevent the use of its territory by non-state militia groups responsible for such attacks."

Estimated Scope/Duration

Scope/duration specified

Details: "on February 25, 2021, United States forces conducted a targeted military strike"

Type of Enemy or Mission

Non-state actor

Details: "Iran-supported non-state militia groups"

Military Activity

Air operations

Details: "United States forces conducted a targeted military strike against infrastructure in eastern Syria used by Iran-supported non-state militia groups"

US Casualties Reported


Details: "Those non-state militia groups were involved in recent attacks against United States and Coalition personnel in Iraq, including the February 15, 2021, attack in Erbil, Iraq, which wounded one United States service member, wounded four United States contractors, including one critically, and killed one Filipino contractor."

Non-US Casualties Reported