For 10 points, name this defensive barrier on the eastern frontier of France which did not stop the Germans during World War II.
The development of this location was overseen by Paul Painleve and was implicitly criticized in the treatise The Army of the Future, which also derided the effectiveness of the citizen-soldier. Most of the 51st Highland Division was taken prisoner near a building at this location in Hackenberg. A plan to augment the defenses of this location involved moving several divisions to the (*) Dyle River. Army Group C conducted a holding action at this place, which allowed Army Groups A and B to move north and then west in the sickle-slice maneuver. Its integrity was compromised once several tank divisions made it through the Ardennes Forest. For 10 points, name this defensive barrier on the eastern frontier of France which did not stop the Germans during World War II.
The development of this location was overseen by Paul Painleve and was implicitly criticized in the treatise The Army of the Future, which also derided the effectiveness of the citizen-soldier.
Maginot Line [or Ligne Maginot]