Operation Green (Ireland)

Operation Green (German: Unternehmen Grün) often also referred to as Case Green (Fall Grün) or Plan Green (Plan Grün), was a full-scale operations plan for a Nazi German invasion of Ireland planned by an unknown German officer known by the alias "Hadel" in support of Operation Sea Lion (Unternehmen Seelöwe), the invasion of the United Kingdom, during World War II. Despite its detailed nature, Operation Green is thought to have been designed only as a credible threat or feint, not an actual operation. The British government, in secret liaison with the Irish government, drafted Plan W, a planned occupation of Ireland by the British Armed Forces to counteract a potential German invasion.

Source: Wikipedia — Operation Green (Ireland) (CC BY-SA 4.0)