ACO
Definition
Allied Command Operations (ACO) within NATO is responsible for planning and executing all Alliance military operations. It is headed by the Supreme Allied Commander Europe (SACEUR) and operates at the strategic, operational, and tactical levels. At SHAPE in Mons, Belgium, ACO works to maintain Alliance territory integrity, safeguard maritime routes, and ensure member state security. Additionally, ACO cooperates with Allied Command Transformation to ensure NATO's capabilities remain relevant and effective in a rapidly changing world. In times of crisis, ACO coordinates joint and combined forces for military operations across multiple levels of command.
Source
https://www.nato.int/cps/en/natohq/topics_52091.htm
Key words
Supreme Allied Commander Europe (SACEUR)
Strategic planning
Military operations