The Italian invasion of France (10–25 June 1940), also called the Battle of the Alps, was the first major Italian engagement of World War II and the last major engagement of the Battle of France.
The Italian entry into the war widened its scope considerably in Africa and the Mediterranean Sea. The goal of the Italian leader, Benito Mussolini, was the elimination of Anglo-French domination in the Mediterranean, the reclamation of historically Italian territory (Italia irredenta) and the expansion of Italian influence over the Balkans and in Africa. France and Britain tried during the 1930s to draw Mussolini away from an alliance with Germany but the rapid German successes from 1938 to 1940 made Italian intervention on the German side inevitable by May 1940.
Italy declared war on France and Britain on the evening of 10 June, to take effect just after midnight. The two sides exchanged air raids on the first day of the war, but little transpired on the Alpine front since France and Italy had defensive strategies. There was some skirmishing between patrols and the French forts of the Ligne Alpine exchanged fire with their Italian counterparts of the Vallo Alpino. On 17 June, France announced that it would seek an armistice with Germany. On 21 June, with a Franco-German armistice about to be signed, the Italians launched a general offensive along the Alpine front, the main attack coming in the northern sector and a secondary advance along the coast. The Italian offensive penetrated a few kilometres into French territory against strong resistance but stalled before its primary objectives could be attained, the coastal town of Menton, situated directly on the Italian border, being the most significant conquest.
On the evening of 24 June, an armistice was signed at Rome. It came into effect just after midnight on 25 June, at the same time as the armistice with Germany (signed 22 June). Italy was allowed to occupy the territory it had captured in the brief fighting, a demilitarised zone was created on the French side of the border, Italian economic control was extended into south-east France up to the Rhône and Italy obtained certain rights and concessions in certain French colonies. An armistice control commission, the Commissione Italiana d'Armistizio con la Francia (CIAF), was set up in Turin to oversee French compliance.
Background
Italian imperial ambitions
During the late 1920s, the Italian Prime Minister Benito Mussolini spoke with increasing urgency about imperial expansion, arguing that Italy needed an outlet for its "surplus population" and that it would therefore be in the best interests of other countries to aid in this expansion. The immediate aspiration of the regime was political "hegemony in the Mediterranean–Danubian–Balkan region", more grandiosely Mussolini imagined the conquest "of an empire stretching from the Strait of Gibraltar to the Strait of Hormuz". Balkan and Mediterranean hegemony was predicated by ancient Roman dominance in the same regions. There were designs for a protectorate over Albania and for the annexation of Dalmatia, as well as economic and military control of Yugoslavia and Greece. The regime also sought to establish protective patron–client relationships with Austria, Hungary, Romania and Bulgaria, which all lay on the outside edges of its European sphere of influence. Although it was not among his publicly proclaimed aims, Mussolini wished to challenge the supremacy of Britain and France in the Mediterranean Sea, which was considered strategically vital, since the Mediterranean was Italy's only conduit to the Atlantic and Indian Oceans.
In 1935, Italy initiated the Second Italo-Ethiopian War, "a nineteenth-century colonial campaign waged out of due time". The campaign gave rise to optimistic talk on raising a native Ethiopian army "to help conquer" Anglo-Egyptian Sudan. The war also marked a shift towards a more aggressive Italian foreign policy and also "exposed [the] vulnerabilities" of the British and French. This in turn created the opportunity Mussolini needed to begin to realize his imperial goals. In 1936, the Spanish Civil War broke out. From the beginning, Italy played an important role in the conflict. Their military contribution was so vast, that it played a decisive role in the victory of the Nationalist forces led by Francisco Franco. Mussolini had engaged in "a full-scale external war" due to the insinuation of future Spanish subservience to the Italian Empire, and as a way of placing the country on a war footing and creating "a warrior culture". The aftermath of the war in Ethiopia saw a reconciliation of German-Italian relations following years of a previously strained relationship, resulting in the signing of a treaty of mutual interest in October 1936. Mussolini referred to this treaty as the creation of a Berlin-Rome Axis, which Europe would revolve around. The treaty was the result of increasing dependence on German coal following League of Nations sanctions, similar policies between the two countries over the conflict in Spain, and German sympathy towards Italy following European backlash to the Ethiopian War. The aftermath of the treaty saw the increasing ties between Italy and Germany, and Mussolini falling under Adolf Hitler's influence from which "he never escaped".
In October 1938, in the aftermath of the Munich Agreement, Italy demanded concessions from France. These included a free port at Djibouti, control of the Addis Ababa–Djibouti railway, Italian participation in the management of Suez Canal Company, some form of French-Italian condominium over French Tunisia, and the preservation of Italian culture on Corsica with no French assimilation of the people. The French refused the demands, believing the true Italian intention was the territorial acquisition of Nice, Corsica, Tunisia, and Djibouti. On 30 November 1938, Foreign Minister Galeazzo Ciano addressed the Chamber of Deputies on the "natural aspirations of the Italian people" and was met with shouts of "Nice! Corsica! Savoy! Tunisia! Djibouti! Malta!" Later that day, Mussolini addressed the Fascist Grand Council "on the subject of what he called the immediate goals of 'Fascist dynamism'." These were Albania; Tunisia; Corsica, an integral part of France; the Ticino, a canton of Switzerland; and all "French territory east of the River Var", including Nice, but not Savoy.
Beginning in 1939 Mussolini often voiced his contention that Italy required uncontested access to the world's oceans and shipping lanes to ensure its national sovereignty. On 4 February 1939, Mussolini addressed the Grand Council in a closed session. He delivered a long speech on international affairs and the goals of his foreign policy, "which bears comparison with Hitler's notorious disposition, minuted by Colonel Hossbach". He began by claiming that the freedom of a country is proportional to the strength of its navy. This was followed by "the familiar lament that Italy was a prisoner in the Mediterranean". He called Corsica, Tunisia, Malta, and Cyprus "the bars of this prison", and described Gibraltar and Suez as the prison guards. To break British control, her bases on Cyprus, Gibraltar, Malta, and in Egypt (controlling the Suez Canal) would have to be neutralized. On 31 March, Mussolini stated that "Italy will not truly be an independent nation so long as she has Corsica, Bizerta, Malta as the bars of her Mediterranean prison and Gibraltar and Suez as the walls." Fascist foreign policy took for granted that the democracies—Britain and France—would someday need to be faced down. Through armed conquest Italian North Africa and Italian East Africa—separated by the Anglo-Egyptian Sudan—would be linked, and the Mediterranean prison destroyed. Then, Italy would be able to march "either to the Indian Ocean through the Sudan and Abyssinia, or to the Atlantic by way of French North Africa".
As early as September 1938, the Italian military had drawn up plans to invade Albania. On 7 April 1939, Italian forces landed in the country and within three days had occupied the majority of the country. Albania represented a territory Italy could acquire for "'living space' to ease its overpopulation" as well as the foothold needed to launch other expansionist conflicts in the Balkans. On 22 May 1939, Italy and Germany signed the Pact of Steel joining both countries in a military alliance. The pact was the culmination of German-Italian relations from 1936 and was not defensive in nature. Rather, the pact was designed for a "joint war against France and Britain", although the Italian hierarchy held the understanding that such a war would not take place for several years. However, despite the Italian impression, the pact made no reference to such a period of peace and the Germans proceeded with their plans to invade Poland.
In September 1939, Britain imposed a selective blockade of Italy. Coal from Germany, which was shipped out of Rotterdam, was declared contraband. The Germans promised to keep up shipments by train, over the Alps, and Britain offered to supply all of Italy's needs in exchange for Italian armaments. The Italians could not agree to the latter terms without shattering their alliance with Germany. On 2 February 1940, however, Mussolini approved a draft contract with the Royal Air Force to provide 400 Caproni aircraft; yet he scrapped the deal on 8 February. The British intelligence officer, Francis Rodd, believed that Mussolini was persuaded to reverse policy by German pressure in the week of 2–8 February, a view shared by the British ambassador in Rome, Percy Loraine. On 1 March, the British announced that they would block all coal exports from Rotterdam to Italy. Italian coal was one of the most discussed issues in diplomatic circles in the spring of 1940. In April Britain began strengthening their Mediterranean Fleet to enforce the blockade. Despite French misgivings, Britain rejected concessions to Italy so as not to "create an impression of weakness". Germany supplied Italy with about one million tons of coal a month beginning in the spring of 1940, an amount that even exceeded Mussolini's demand of August 1939 that Italy receive six million tons of coal for its first twelve months of war.
Battle of France
On 1 September 1939, Germany invaded Poland. Following a month of war, Poland was defeated. A period of inaction, called the Phoney War, then followed between the Allies and Germany. On 10 May 1940, this inactivity ended as Germany began Fall Gelb (Case Yellow) against France and the neutral nations of Belgium, the Netherlands and Luxembourg. On 13 May, the Germans fought the Battle of Sedan and crossed the Meuse. The Germans rapidly encircled the northern Allied armies. On 27 May, Anglo-French forces trapped in the north began the Dunkirk evacuation, abandoning their heavy equipment in the process. Following the Dunkirk evacuation, the Germans continued their offensive towards Paris with Fall Rot (Case Red). With over 60 divisions, compared to the remaining 40 French divisions in the north, the Germans were able to breach the French defensive line along the river Somme by 6 June. Two days later, Parisians could hear distant gunfire. On 9 June, the Germans entered Rouen, in Upper Normandy. The following day, the French Government abandoned Paris, declaring it an open city, and fled to Bordeaux.
Italian declaration of war
On 23 January 1940, Mussolini remarked that "even today we could undertake and sustain a ... parallel war", having in mind a war with Yugoslavia, since on that day Ciano had met with the dissident Croat Ante Pavelić. A war with Yugoslavia was considered likely by the end of April. On 26 May, Mussolini informed Marshals Pietro Badoglio, chief of the Supreme General Staff, and Italo Balbo that he intended to join the German war against Britain and France, so to be able to sit at the peace table "when the world is to be apportioned" following an Axis victory. The two marshals unsuccessfully attempted to persuade Mussolini that this was not a wise course of action, arguing that the Italian military was unprepared, divisions were not up to strength, troops lacked equipment, the empire was equally unprepared, and the merchant fleet was scattered across the globe. On 5 June, Mussolini told Badoglio, "I only need a few thousand dead so that I can sit at the peace conference as a man who has fought". According to the post-war memoires of Paul Paillole, in 1940 a captain in the French military intelligence, the Deuxième Bureau, he was forewarned about the Italian declaration of war on 6 June, when he met Major Navale, an Italian intelligence officer, on the Pont Saint-Louis to negotiate an exchange of captured spies. When Paillole refused Navale's proposal, the major warned him that they only had four days to work something out before war would be declared, although nothing much would happen near Menton before 19/20 June.
By mid-1940 Germany had revised its earlier preference for Italy as a war ally. The pending collapse of France might have been affected by any diversion of German military resources to support a new Alpine front. From a political and economic perspective, Italy was useful as a sympathetic neutral and her entry into the war might complicate any peace negotiations with Britain and France.