On September 27, 1940, Germany, Italy, and Japan signed the Tripartite Pact, a mutual assistance treaty where the signatories pledged to come to the aid “if one of the Contracting Powers is attacked by a Power at present not involved in the European War or in the Japanese-Chinese conflict.” At this time, Europe was already embroiled in World War II while in Asia, the Second-Japanese War was being fought. The Pact was directed at the United States, which was then the only neutral major power, to deter its being involved in the conflicts on the Allied side. The Pact also acknowledged the pre-eminence of Germany and Italy in Europe, and Japan in “Greater East Asia”. It was to be effective for ten years, with a provision for its renewal.
The Tripartite Pact was later joined by other countries: Hungary on November 20, 1940, Romania on November 23, 1940, Slovakia on November 24, 1940, Bulgaria on March 1, 1941, and Yugoslavia on March 25, 1941. The Axis invaded and then partitioned Yugoslavia; subsequently, the newly formed Independent State of Croatia joined the Pact on June 15, 1941.
The Soviet Union also entered into negotiations with Germany to join the Tripartite Pact, even offering the latter substantial economic concessions. However, Hitler was determined that the Soviet Union would not be allowed to join, as preparations were already underway for Operation Barbarossa.
In June 1941, after the start of the German-led invasion of the Soviet Union, Germany asked Finland, which had also participated in the attack, to join the Tripartite Pact. However, the Finnish government rebuffed the offer, as its military objectives differed from the Germans. Finland also wanted to maintain diplomatic relations with the United States and the Western Allies.
Japan attacked Thailand on December 8, 1941 as a means to gain passage to invasion British Malaya and Burma. After a ceasefire was signed, Japan invited Thailand to join the Tripartite Pact, but the latter only agreed on military cooperation with the Japanese.
(Taken from Italy before World War II – Wars of the 20th Century- World War II in Europe)
In World War I, Italy had joined the Allies under a secret agreement (the 1915 Treaty of London) in that it would be rewarded with the coastal regions of Austria-Hungary after victory was achieved. But after the war, in the peace treaties with Austria-Hungary and Germany, the victorious Allies reneged on this treaty, and Italy was awarded much less territory than promised. Indignation swept across Italy, and the feeling of the so-called “mutilated victory” relating to Italy’s heavy losses in the war (1.2 million casualties and steep financial cost) led to the rise in popularity of ultra-nationalist, right-wing, and irredentist ideas. Italian anger over the war paved the way for the coming to power of the Fascist Party, whose leader Benito Mussolini became Prime Minister in October 1922. The Fascist government implemented major infrastructure and social programs that made Mussolini extremely popular. In a few years, Mussolini ruled with near absolute powers in a virtual dictatorship, with the legislature abolished, political dissent suppressed, and his party the sole legal political party. Mussolini also made gains in foreign affairs: in the Treaty of Lausanne (July 1923) that ended World War II between the Allies and Ottoman Empire, Italy gained Libya and the Dodecanese Islands. In August 1923, Italian forces occupied Greece’s Corfu Island, but later withdrew after League of Nations mediation and the Greek government’s promise to pay reparations.
In the late 1920s onward, Mussolini advocated grandiose expansionism to establish a modern-day Italian Empire, which would include plans to annex Balkan territories that had formed part of the ancient Roman Empire, gaining a sphere of influence in parts of Central and Eastern Europe, achieving mastery over the Mediterranean Sea, and gaining control of North Africa and the Middle East which would include territories stretching from the Atlantic Ocean in the west to the Indian Ocean in the east.
With the Nazis coming to power in Germany in 1933, Hitler and Mussolini, with similar political ideologies, initially did not get along well, and in July 1934, they came into conflict over Austria. There, Austrian Nazis attempted a coup d’état, assassinating Chancellor Engelbert Dollfuss and demanding unification with Germany. Mussolini, who saw Austria as falling inside his sphere of influence, sent troops, tanks, and planes to the Austrian-Italian border, poised to enter Austria if Germany invaded. Hitler, at this time still unprepared for war, backed down from his plan to annex Austria. Then in April 1935, Italy banded together with Britain and France to form the Stresa Front (signed in Stresa, Italy), aimed as a united stand against Germany’s violations of the Versailles and Locarno treaties; one month earlier (March 1935), Hitler had announced his plan to build an air force, raise German infantry strength to 550,000 troops, and introduce military conscription, all violations of the Versailles treaty.
However, the Stresa Front quickly ended in fiasco, as the three parties were far apart in their plans to deal with Hitler. Mussolini pressed for aggressive action; the British, swayed by anti-war public sentiments at home, preferred to negotiate with Hitler; and France, fearful of a resurgent Germany, simply wanted an alliance with the others. Then in June 1935, just two months after the Stresa Front was formed, Britain and Germany signed a naval treaty (the Anglo-German Naval Agreement), which allowed Germany to build a navy 35% (by tonnage) the size of the British navy. Italy (as well as France) was outraged, as Britain was openly allowing Hitler to ignore the Versailles provision that restricted German naval size. Mussolini, whose quest for colonial expansion was only restrained by the reactions from both the British and French, saw the naval agreement as British betrayal to the Stresa Front. To Mussolini, it was a green light for him to launch his long desired conquest of Ethiopia (then also known as Abyssinia). In October 1935, Italy invaded Ethiopia, overrunning the country by May 1936 and incorporating it into newly formed Italian East Africa. In November 1935, the League of Nations, acting on a motion by Britain that was reluctantly supported by France, imposed economic sanctions on Italy, which angered Mussolini, worsening Italy’s relations with its Stresa Front partners, especially Britain. At the same time, since Hitler gave his support to Italy’s invasion of Ethiopia, Mussolini was drawn to the side of Germany. In December 1937, Mussolini ended Italy’s membership in the League of Nations, citing the sanctions, despite the League’s already lifting the sanctions in July 1936.
In January 1936, Mussolini informed the German government that he would not oppose Germany extending its sphere of influence in Austria (Germany annexed Austria in March 1938). And in February 1936, Mussolini assured Hitler that Italy would not invoke the Versailles and Locarno treaties if Germany remilitarized the Rhineland. In March 1936, Hitler did just that, eliciting no hostile response from Britain or France. Then in the Spanish Civil War, which started in July 1936, Italy and Germany provided weapons and troops to the right-wing Nationalist forces that rebelled against the Soviet Union-backed leftist Republican government. In April 1939, the Nationalists emerged victorious, and their leader General Francisco Franco formed a fascist dictatorship in Spain.
In October 1936, Italy and Germany signed a political agreement, and Mussolini announced that “all other European countries would from then on rotate on the Rome-Berlin Axis”, with the term “Axis” later denoting this alliance, which included Japan as well as other minor powers. In May 1939, German-Italian relations solidified into a formal military alliance, the “Pact of Steel”. In November 1937, Italy joined the Anti-Comintern Pact, which Germany and Japan signed one year earlier (November 1936), ostensibly only directed against the Communist International (Comintern), but really targeting communist ideology and by extension, the Soviet Union. In September 1940, the Axis Powers were formed, with Germany, Italy, and Japan signing the Tripartite Pact.
In April 1939, Italy invaded Albania (separate article), gaining full control within a few days, and the country was joined politically with Italy as a separate kingdom in personal union with the Italian crown. Six months later (September 1939), World War II broke out in Europe, which took Italy completely by surprise.
Despite its status as a major military power, Italy was unprepared for war. It had a predominantly agricultural economy, and industrial production for war-convertible commodities amounted to just 15% that of Britain and France. As well, Italian capacity for war-important items such as coal, crude oil, iron ore, and steel lagged far behind those of other western powers. In military capability, Italian tanks, artillery, and aircraft were inferior and mostly obsolete, although the Italian Navy was large, ably powerful, and possessed several modern battleships. Cognizant of Italian military deficiencies, Mussolini placed great efforts to build up armed strength, and by 1939, some 40% of the national budget was allocated to national defense. Even so, Italian military planners had projected that full re-armament and building up of their forces would be completed only in 1943; thus, the unexpected start of World War II in September 1939 came as a shock to Mussolini and the Italian High Command.