General Maurice Gamelin, when drafting the Dyle Plan, believed this region, with its rough terrain, would be an unlikely invasion route of German forces; if it were traversed, it would be done at a slow rate that would allow the French time to bring up reserves and counterattacks.

This consisted of blockhouses and strong-houses, which were often camouflaged as residential homes, built within a few metres of the border and manned by troops to give the alarm in the event of a surprise attack and to delay enemy tanks with prepared explosives and barricades.

Approximately 5 km (3 mi) behind the border there was a line of anti-tank blockhouses that were intended to provide resistance to armoured assault, sufficient to delay the enemy and allow time for the crews of the C.O.R.F.

The petits ouvrages were generally made up of several infantry bunkers, connected by a tunnel network with attached underground facilities, such as barracks, electric generators, ventilation systems, mess halls, infirmaries and supply caches.

These are large reinforced buried concrete bunkers, equipped with armoured turrets containing high-precision optics, connected with the other fortifications by field telephone and wireless transmitters (known in French by the acronym T.S.F., Télégraphie Sans Fil).

These were built near the major fortifications so fortress (ouvrage) crews could reach their battle stations in the shortest possible time in the event of a surprise attack during peacetime.

At a conference in London in 1924 to settle the Franco-German crisis caused by the Ruhrkampf, the British Prime Minister Ramsay MacDonald successfully pressed the French Premier Édouard Herriot to make concessions to Germany.

The British diplomat Sir Eric Phipps, who attended the conference, commented afterwards that: The London Conference was for the French 'man in the street' one long Calvary as he saw M. Herriot abandoning one by one the cherished possessions of French preponderance on the Reparations Commission, the right of sanctions in the event of German default, the economic occupation of the Ruhr, the French-Belgian railway Régie, and finally, the military occupation of the Ruhr within a year.

[citation needed] The German statement following The Manchester Guardian's article that Germany did not feel bound by the terms of Versailles and would violate them as much as possible gave much offence in France.

Nonetheless, in 1927, the Inter-Allied Commission, which was responsible for ensuring that Germany complied with Part V of the Treaty of Versailles, was abolished as a goodwill gesture reflecting the "Spirit of Locarno".

[16] When the Control Commission was dissolved, the commissioners in their final report issued a blistering statement, stating that Germany had never sought to abide by Part V and the Reichswehr had been engaging in covert rearmament all through the 1920s.

[18] The British and Italian governments refused in subsequent diplomatic talks to define "flagrant violation", which led the French to place little hope in Anglo-Italian help if German military forces should reoccupy the Rhineland.

[18] Given the diplomatic situation in the late 1920s, the Quai d'Orsay informed the government that French military planning should be based on a worst-case scenario that France would fight the next war against Germany without the help of Britain or the United States.

The French military was especially insistent that the population disparity made an offensive war of manoeuvre and swift advances suicidal, as there would always be far more German divisions; a defensive strategy was needed to counter Germany.

[20] The drop in the birth rate during and after the war, resulting in a national shortage of young men, created an "echo" effect on the generation that provided the French conscript army in the mid-1930s.

[24] The Germans were expected to fight costly offensives, whose failures would sap the strength of the Reich, while the French waged a total war, mobilising the resources of France, its empire and allies.

[27] For economic reasons, the success of the strategy of la guerre de longue durée would at the very least require Britain to maintain a benevolent neutrality, preferably to enter the war as an ally as British sea power could protect French imports while depriving Germany of hers.

[28] The line was built in several phases from 1930 by the Service Technique du Génie (STG), overseen by Commission d'Organisation des Régions Fortifiées (CORF).

The original construction did not cover the area ultimately chosen by the Germans for their first challenge, which was through the Ardennes in 1940, a plan known as Fall Gelb (Case Yellow), due to the neutrality of Belgium.

In contrast, the propaganda about the line made it appear far greater a construction than it was; illustrations showed multiple storeys of interwoven passages and even underground rail yards and cinemas.

A decoy force sat opposite the line while a second Army Group cut through the Low Countries of Belgium and the Netherlands, as well as through the Ardennes Forest, which lay north of the main French defences.

During the advance to the English Channel, the Germans overran France's border defence with Belgium and several Maginot Forts in the Maubeuge area whilst the Luftwaffe simply flew over it.

On 19 May, the German 16th Army captured the isolated petit ouvrage La Ferté (south-east of Sedan) after conducting a deliberate assault by combat engineers backed up by heavy artillery, taking the fortifications in only four days.

On 15 June, infantry divisions of the German 7th Army attacked across the Rhine River in Operation "Small Bear", deeply penetrating the defences and capturing the cities of Colmar and Strasbourg.

When the Allied forces invaded in June 1944, the line, now held by German defenders, was again largely bypassed; fighting touched only portions of the fortifications near Metz and in northern Alsace towards the end of 1944.

[31] In January 1945 von Luck with 21 Panzerdivision was tasked with cutting through the old Maginot Line defences and severing Allied links with Strasbourg as part of Operation Nordwind.

In 1968, when scouting locations for On Her Majesty's Secret Service, producer Harry Saltzman used his French contacts to gain permission to use portions of the Maginot Line as SPECTRE headquarters in the film.

Kaufmann added that before construction in October 1927, the Superior Council of War adopted the final design for the line and identified that one of the main missions would be to deter a German cross-border assault with only minimal force to allow "the army time to mobilise.

[38] In support, Roth commented that the French strategy envisioned one of two possibilities by advancing into Belgium: "either there would be a decisive battle in which France might win, or, more likely, a front would develop and stabilise".

Its enormous cost and its failure to prevent German forces from invading France have caused journalists and political commentators to remain divided on whether the line was worthwhile.