NATO's Supreme Allied Commander Europe: Role and Responsibilities (nato.int)

• SACEUR is responsible for overall command of NATO military operations.
• Appointed by US President, confirmed by US Senate, approved by North Atlantic Council.
• Reports to NATO's Military Committee and has direct access to Chiefs of Defence.
• In case of aggression, SACEUR executes all military measures to restore security.
• First SACEUR was General Dwight D. Eisenhower in 1951.

"The Supreme Allied Commander Europe (SACEUR) is one of NATO's two strategic commanders, responsible for all NATO military operations. Appointed by the US President and confirmed by the US Senate, SACEUR reports to NATO's Military Committee and has direct access to national authorities. The role includes planning operations, requesting forces, and executing military measures in case of aggression. SACEUR also serves as senior military spokesperson. The first SACEUR was General Dwight D. Eisenhower in 1951."