Before World War II, Fall Grün (Case Green) was a German plan for an aggressive war against Czechoslovakia in 1938. However, because of the Munich Agreement, it wasn't executed (with only days left to its start).
As Czechoslovakia ceded Sudetenland to Germany, it lost the most of its border fortifications and was no longer in a defendable position. Eventually, it was annexed to the Reich on March 15, 1939 (Unternehmen Südost) with minimal resistance.
See also: Operation Grün (Ireland)
