Final answer:
Critical sections of the French border during World War II included the Maginot Line, the region around Dunkirk, and the area east of the Marne River, each of which played a key role in the dynamics of the war.
Step-by-step explanation:
The section of the French border that was critical to winning the war refers to several key areas during World War II. Initially, the French and British forces focused on defending France against the German army.
The Maginot Line was a prominent defensive structure built by the French along the German border, intended to be impregnable.
However, the Germans outmaneuvered the Allies by attacking through Belgium and the Ardennes Forest, effectively sidestepping the fortified Maginot Line.
The resulting German advance through the Ardennes was a crucial turning point due to the rapid movement of German forces and the consequent disorientation of the Allied defenses.
Another critical section was near the city of Dunkirk, where the Germans aimed to flank the Allied position in Northern France, exposing nearly the entire British Expeditionary Force to attack from German warplanes.
The perilous situation led to the legendary Dunkirk evacuation, where a significant number of Allied troops were rescued and taken back to Britain, which was seen as a turning point in maintaining British and French morale and fighting capacity.
The area east of the Marne River also played a vital role in the early part of the war. At the First Battle of the Marne, the Allies managed to stop the German advance, setting up defensive trenches and initiating the static trench warfare that characterized much of the Western Front during World War I.