Editing Maginot Line (section)

=== Planning and construction ===
[[File:Maginot Line ln-en.svg|thumb|The Maginot Line]]
The defences were first proposed by Marshal [[Joseph Joffre]]. He was opposed by modernists such as [[Paul Reynaud]] and [[Charles de Gaulle]], who favoured investment in armour and aircraft. Joffre had support from Marshal [[Henri Philippe Pétain]], and the government organised many reports and commissions. [[André Maginot]] finally convinced the government to invest in the scheme. Maginot was another veteran of World War I; he became the [[Minister of Veterans Affairs (France)|French Minister of Veteran Affairs]] and then [[Minister of War (France)|Minister of War]] (1928–1932).

In January 1923, after [[Weimar Republic|Weimar Germany]] defaulted on [[World War I reparations|reparations]], the French Premier [[Raymond Poincaré]] responded by sending French troops to occupy Germany's [[Ruhr]] region. During the ensuing ''Ruhrkampf'' ("Ruhr struggle") between the Germans and the French that lasted until September 1923, Britain condemned the [[Occupation of the Ruhr|French occupation of the Ruhr]]. A period of sustained [[Francophobia]] broke out in Britain, with Poincaré being vilified in Britain as a cruel bully punishing Germany with unreasonable reparations demands. The British—who openly championed the German position on reparations—applied intense economic pressure on France to change its policies towards Germany. 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: <blockquote>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.{{sfn|Marks|1978|p=249}}</blockquote> The great conclusion that was drawn in Paris after the ''Ruhrkampf'' and the 1924 London Conference was that France could not make unilateral military moves to uphold [[Treaty of Versailles|Versailles]] as the resulting British hostility to such moves was too dangerous to the republic. Beyond that, the French were well aware of the contribution of Britain and its dominions to the victory of 1918. French decision-makers believed they needed Britain's help to win another war; the French could only go so far with alienating the British.{{sfn|Young|2005|p=20}} From 1871 forward, French elites had concluded that France had no hope of defeating Germany on its own, and France would need an alliance with another great power to defeat the ''Reich''.{{sfn|Smith|Audoin-Rouzeau|Becker|2003|p=11}}

==== 1927: Allied Control Commission abolished ====
In 1926, ''[[The Guardian|The Manchester Guardian]]'' ran an [[Exposé (journalism)|exposé]] showing the ''[[Reichswehr]]'' had been developing military technology forbidden by the [[Treaty of Versailles]] in the [[Soviet Union]]. The secret German-Soviet cooperation started in 1921.{{Citation needed|date=December 2023}} 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 [[Military Inter-Allied Commission of Control|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 Treaties|Locarno]]".{{sfn|Keylor|2001|p=121}} 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. Under the Treaty of Versailles, France was to occupy the Rhineland region of Germany until 1935. Still, the last French troops left the Rhineland in June 1930 in exchange for Germany accepting the [[Young Plan]].{{sfn|Keylor|2001|pp=121–122}} As long as the French occupied the Rhineland, it served as a type of collateral under which the French would annex the Rhineland in the event of Germany breaching any of the articles of the treaty, such as rearming in violation of Part V; this threat was powerful enough to deter successive German governments all through the 1920s from attempting any overt violation of Part V.{{sfn|Keylor|2001|p=122}} French plans as developed by Marshal [[Ferdinand Foch]] in 1919 were based on the assumption that in the event of a war with the ''Reich'', the French forces in the Rhineland were to embark upon an offensive to seize the Ruhr.{{sfn|Keylor|2001|p=122}} A variant of the Foch plan had been used by Poincaré in 1923 when he ordered the French occupation of the Ruhr.{{sfn|Keylor|2001|p=122}}

French plans for an offensive in the 1920s were realistic, as Versailles had forbidden [[Conscription in Germany|German conscription]], and the ''Reichswehr'' was limited to 100,000 men. Once the French forces left the [[Rhineland]] in 1930, this form of leverage with the Rhineland as collateral was no longer available to Paris, which from then on had to depend on Berlin's word that it would continue to abide by the terms of the Versailles and Locarno treaties, which stated that the Rhineland was to stay demilitarised forever.{{sfn|Keylor|2001|p=122}} Given that Germany had engaged in [[German re-armament|covert rearmament]] with the co-operation of the Soviet Union starting in 1921 (a fact that had become public knowledge in 1926) and that every German government had gone out of its way to insist on the moral invalidity of Versailles, claiming it was based upon the so-called ''Kriegsschuldlüge'' ("War guilt lie") that Germany started the war in 1914, the French had little faith that the Germans would willingly allow the Rhineland's demilitarised status to continue forever, and believed that at some time in the future, Germany would rearm in violation of Versailles, reintroduce conscription and remilitarise the Rhineland.{{sfn|Keylor|2001|p=122}} The decision to build the Maginot Line in 1929 was a tacit French admission that without the Rhineland as collateral, Germany was soon going to rearm and that the terms of Part V had a limited lifespan.{{sfn|Keylor|2001|p=122}}

==== German economic superiority ====
After 1918, the German economy was twice as large as that of France; Germany had a population of 70 million compared to France's 40 million, and the [[Economy of France|French economy]] was hobbled by the need to reconstruct the enormous damage of World War I, while German territory had seen little fighting. French military chiefs were dubious about their ability to win another war against Germany on its own, especially an offensive war.{{sfn|Keylor|2001|p=122}} French decision-makers knew that the victory of 1918 had been achieved because the British Empire and the United States were allies in the war and that the French would have been defeated on their own.{{sfn|Keylor|2001|pp=121–122}} With the United States isolationist and Britain stoutly refusing to make the "continental commitment" to defend France on the same scale as in World War I, the prospects of Anglo-American assistance in another war with Germany appeared to be doubtful at best.{{sfn|Keylor|2001|pp=121–122}} Versailles did not call for military sanctions in the event of the German military reoccupying the Rhineland or breaking Part V, while Locarno committed Britain and Italy to come to French aid in the event of a "flagrant violation" of the Rhineland's demilitarised status, it did not define what a "flagrant violation" would be.{{sfn|Keylor|2001|p=122}} 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.{{sfn|Keylor|2001|p=122}} 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.{{sfn|Keylor|2001|p=122}}

France had an alliance with [[Belgium]] and with the states of the ''[[Cordon sanitaire (international relations)|Cordon sanitaire]]'', as the French alliance system in [[Eastern Europe]] was known. Although the alliances with Belgium, [[Second Polish Republic|Poland]], [[First Czechoslovak Republic|Czechoslovakia]], [[Kingdom of Romania|Romania]] and [[Kingdom of Yugoslavia|Yugoslavia]] were appreciated in Paris, it was widely understood that this was no compensation for the absence of Britain and 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.{{sfn|Keylor|2001|p=122}} The French assumption was always that Germany would not go to war without conscription, which would allow the German Army to take advantage of the ''Reich''{{'}}s numerical superiority. Without the natural defensive barrier provided by the [[Rhine]] River, French generals argued that France needed a new defensive barrier made of concrete and steel to replace it.{{sfn|Keylor|2001|p=122}} The power of properly dug-in defensive trenches had been amply demonstrated during World War I, when a few soldiers manning a single machine gun post could kill hundreds of the enemy in the open and therefore building a massive defensive line with subterranean concrete shelters was the most rational use of French manpower.{{sfn|Keylor|2001|p=123}}

The American historian William Keylor wrote that given the diplomatic conditions of 1929 and likely trends – with the United States [[United States non-interventionism|isolationist]] and Britain unwilling to make the "continental commitment" – the decision to build the Maginot Line was not irrational and stupid, as building the Maginot Line was a sensible response to the problems that would be created by the coming French withdrawal from the Rhineland in 1930.{{sfn|Keylor|2001|p=123}} Part of the rationale for the Maginot Line stemmed from the severe French losses during the First World War and their effect on the French population.{{sfn|Young|2005|p=13}} 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.{{sfn|Young|2005|p=13}} Faced with a manpower shortage, French planners had to rely more on older and less fit [[reservist]]s, who would take longer to mobilise and would diminish the French industry because they would leave their jobs. Static defensive positions were therefore intended not only to buy time but to economise on men by defending an area with fewer and less mobile forces. However, in 1940, France deployed about twice as many men, 36 divisions (roughly one third of its force), for the defence of the Maginot Line in Alsace and Lorraine. In contrast, the opposing German [[Army Group C]] only contained 19 divisions, fewer than a seventh of the force committed in the [[Manstein Plan]] for the invasion of France.{{sfn|Frieser |2005|p=88}} Reflecting memories of World War I, the French General Staff had developed the concept of ''la puissance du feu'' ("the power of fire"), the power of [[artillery]] dug in and sheltered by concrete and steel, to inflict devastating losses on an attacking force.{{sfn|Young|2005|p=36}}

==== Preparing for a long war ====
French planning for war with Germany was always based on the assumption that the war would be [[Attrition warfare|''la guerre de longue durée'' (the long war)]], in which the superior economic resources of the Allies would gradually grind the Germans down.{{sfn|Young|2005|p=35}} The fact that the ''Wehrmacht'' embraced the strategy of [[Blitzkrieg]] (Lightning War) with the vision of swift wars in which Germany would win quickly via a knockout blow was a testament to the fundamental soundness of the concept of ''la guerre de longue durée''.{{sfn|Young|2005|p=35}} Germany had the largest economy in Europe but lacked many of the raw materials necessary for a modern industrial economy (making the ''Reich'' vulnerable to a blockade) and the ability to feed its population. The ''guerre de longue durée'' strategy called for the French to halt the expected German offensive meant to give the ''Reich'' a swift victory; afterwards, there would be an attrition struggle; once the Germans were exhausted, France would begin an offensive to win the war.{{sfn|Young|2005|p=35}}

The Maginot Line was intended to block the main German blow if it should come via eastern France and divert it through Belgium, where French forces would meet and stop the Germans.{{sfn|Young|2005|pp=35–36}} 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.{{sfn|Young|2005|p=37}} Besides the demographic reasons, a defensive strategy served the needs of French diplomacy towards Great Britain.{{sfn|Young|2005|p=40}} The French imported a third of their [[coal]] from Britain, and 32 per cent of all imports through French ports were carried by British ships.{{sfn|Young|2005|p=40}} Of French trade, 35 per cent was with the [[British Empire]] and the majority of the [[tin]], [[Natural rubber|rubber]], [[jute]], [[wool]] and [[manganese]] used by France came from the British Empire.{{sfn|Young|2005|p=40}}

About 55 per cent of overseas imports arrived in France via the Channel ports of [[Calais]], [[Le Havre]], [[Cherbourg-Octeville|Cherbourg]], [[Boulogne-sur-Mer|Boulogne]], [[Dieppe]], [[Saint-Malo]] and [[Dunkirk]].{{sfn|Young|2005|p=40}} Germany had to import most of its iron, rubber, [[Petroleum|oil]], [[bauxite]], copper and [[nickel]], making [[Blockade|naval blockade]] a devastating weapon against the [[Economy of Germany|German economy]].{{sfn|Young|2005|p=33}} 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. A defensive strategy based on the Maginot Line was an excellent way of demonstrating to Britain that France was not an aggressive power and would only go to war in the event of German aggression, a situation that would make it more likely that Britain would enter the war on France's side.{{sfn|Young|2005|pp=40–41}}

[[File:Maginot Linie Karte.jpg|The principal fortified section of the Maginot Line|thumb]]
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 main construction was largely completed by 1939, at the cost of around 3 [[1000000000 (number)|billion]] [[French franc]]s (around 3.9 billion in today's U.S. dollar’s worth).{{clarify|date=February 2011|reason=see "Cost of construction" section on the talk page}} The line stretched from [[Switzerland]] to [[Luxembourg]] and a much lighter extension was extended to the [[Strait of Dover]] after 1934. 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. The location of this attack, chosen because of the location of the Maginot Line, was through the Belgian Ardennes Forest (sector 4), which is off the map to the left of Maginot Line sector 6 (as marked).

==== Features ====
[[File:Fort Saint-Gobain p1410129.jpg|thumb|{{convert|81|mm|in|abbr=on}} [[mortar (weapon)|mortar]]]]
The specification of the defences was very high, with extensive and interconnected [[bunker]] complexes for thousands of men; there were 45 main [[fort]]s (''grands ouvrages'') at intervals of {{convert|15|km|mi|abbr=on}}, 97 smaller forts (''petits ouvrages'') and 352 [[casemates]] between, with over {{convert|100|km|mi|abbr=on}} of [[tunnel]]s. Artillery was coordinated with protective measures to ensure that one fort could support the next in line by bombarding it directly without harm. The largest guns were, therefore {{convert|135|mm|in|abbr=on}} fortress guns; larger weapons were to be part of the mobile forces and were to be deployed behind the lines.

The fortifications did not extend through the Ardennes Forest (which was believed to be impenetrable by Commander-in-Chief [[Maurice Gamelin]]) or along France's border with Belgium because the two countries had signed an alliance in 1920, by which the French army would operate in Belgium if the German forces invaded. However, after France had failed to counter the [[Remilitarization of the Rhineland|German remilitarisation of the Rhineland]], Belgium—thinking that France was not a reliable ally—abrogated the treaty in 1936 and declared [[Neutral country|neutrality]]. France quickly extended the Maginot Line along the Franco-Belgian border, but not to the standard of the rest of the line. As the [[water table]] in this region is high, there was the danger of underground passages getting flooded, which the line designers knew would be difficult and expensive to overcome.

In 1939 [[United States Army|U.S. Army]] officer [[Kenneth Nichols]] visited the [[Metz]] sector, where he was impressed by the formidable formations which he thought the Germans would have to outflank by driving through Belgium. In discussion with General Brousseau, the commander of the [[Metz]] sector and other officers, the general outlined the French problem in extending the line to the sea in that placing the line along the Belgian-German border required the agreement of Belgium, but putting the line along the French-Belgian border relinquished Belgium to the Germans. Another complication was Holland, and the various governments never resolved their problems.{{sfn|Nichols|1987|p=27}}

[[File:Fort Saint-Gobain p1410059.jpg|thumb|Corridor inside the Fort Saint-Gobain near [[Modane]] in the [[Alps]]. The [[Decauville]]]]
When the [[British Expeditionary Force (World War II)|British Expeditionary Force]] landed in France in September 1939, they and the French reinforced and extended the Maginot line to the sea in a flurry of construction from 1939 to 1940, accompanied by general improvements all along the line. The final line was strongest around the industrial regions of [[Metz]], [[Lauter (Rhine)|Lauter]] and [[Alsace]], while other areas were, in comparison, only weakly guarded. 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 yard]]s and [[Movie theater|cinemas]]. This reassured allied civilians.

==== Czechoslovak connection ====
[[Czechoslovakia]] also feared Hitler and began building its own defences. As an ally of France, they got advice on the Maginot design and applied it to [[Czechoslovak border fortifications]]. The design of the casemates is similar to the ones found in the southern part of the Maginot Line, and photographs of them are often confused with Maginot forts. Following the [[Munich Agreement]] and the [[German occupation of Czechoslovakia]], the Germans were able to use the Czech fortifications to plan attacks that proved successful against the western fortifications (the Belgian [[Fort Eben-Emael]] is the best-known example).