In the context of the history of the 20th century, the interwar period was the period between the end of the First World War (1914–18) and the beginning of the Second World War (1939–45)—the period beginning with the Armistice of 11 November 1918 that concluded the First World War and the ensuing Paris Peace Conference in 1919, and ending in September 1939 with the German invasion of Poland and the start of the World War II.
Turmoil in Europe
The years 1919-24 were marked by turmoil as Europe struggled to recover from the devastation of the First World War and the destabilising effects of the loss of four large historic empires: the German Empire, Austro-Hungarian Empire, Russian Empire and the Ottoman Empire. There were numerous new nations in Eastern Europe, most of them small in size. The United States gained dominance in world finance. Thus, when Germany could no longer afford war reparations to Britain, France and other Allies, the Americans came up with the Dawes Plan and Wall Street invested heavily in Germany, which repaid its reparations to nations that, in turn, used the dollars to pay off their war debts to Washington. By the middle of the decade, prosperity was widespread, with the second half of the decade known, especially in Germany, as the "Golden Twenties".
The important stages of interwar diplomacy and international relations included resolutions of wartime issues, such as reparations owed by Germany and boundaries; American involvement in European finances and disarmament projects; the expectations and failures of the League of Nations; the relationships of the new countries to the old; the distrustful relations of the Soviet Union to the capitalist world; peace and disarmament efforts; responses to the Great Depression starting in 1929; the collapse of world trade; The collapse of democratic regimes one by one; the growth of economic autarky; Japanese aggressiveness toward China; Fascist diplomacy, including the aggressive moves by Mussolini'a Italy and Hitler's Germany; the Spanish Civil War; the appeasement of Germany's expansionist moves toward the Rhineland, Austria, and Czechoslovakia, and the last, desperate stages of rearmament as the second world war increasingly loomed.
The "Roaring Twenties" highlighted novel and highly visible social and cultural trends and innovations. These trends, made possible by sustained economic prosperity, were most visible in major cities like New York, Chicago, Paris, Berlin and London. Jazz music blossomed, and Art Deco peaked. For women, knee-length skirts and dresses became socially acceptable, as did bobbed hair with a marcel wave. The women who pioneered these trends were frequently referred to as flappers. Not all was new: “normalcy” returned to politics in the wake of hyper-emotional wartime passions in the United States, France, and Germany. The leftist revolutions in Finland, Poland, Germany, Austria, Hungary and Spain were defeated by conservatives, but succeeded in Russia, which became the base for Soviet Communism. In Italy the fascists came to power under Mussolini after threatening a march on Rome.
Most independent countries enacted women's suffrage in the interwar era, including Canada in 1917, Britain in 1918 and the United States in 1920. There were a few major countries that held out until after the Second World War (such as France, Switzerland and Portugal). Leslie Hume argues:
- The women's contribution to the war effort challenged the notion of women's physical and mental inferiority and made it more difficult to maintain that women were, both by constitution and temperament, unfit to vote. If women could work in munitions factories, it seemed both ungrateful and illogical to deny them a place in the polling booth. But the vote was much more than simply a reward for war work; the point was that women's participation in the war helped to dispel the fears that surrounded women's entry into the public arena.
In Europe, according to Derek Aldcroft and Steven Morewood, "Nearly all countries registered some economic progress in the 1920s and most of them managed to regain or surpass their pre-war income and production levels by the end of the decade." The Netherlands, Norway, Sweden, Switzerland and Greece did especially well, while Eastern Europe did poorly. In advanced economies the prosperity reached middle class households and many in the working class. with radio, automobiles, telephones, and electric lighting and appliances. There was unprecedented industrial growth, accelerated consumer demand and aspirations, and significant changes in lifestyle and culture. The media began to focus on celebrities, especially sports heroes and movie stars. Major cities built large sports stadiums for the fans, in addition to palatial cinemas.
The Great Depression was a severe worldwide economic depression that took place during the 1930s. The timing varied across nations; in most countries it started in 1929 and lasted until the late 1930s. It was the longest, deepest, and most widespread depression of the 20th century. The depression originated in the United States, after a slow decline in lofty stock prices and became worldwide news with the stock market crash of October 29, 1929 (known as Black Tuesday). Between 1929 and 1932, worldwide GDP fell by an estimated 15%. By comparison, worldwide GDP fell by less than 1% from 2008 to 2009 during the Great Recession. Some economies started to recover by the mid-1930s. However, in many countries, the negative effects of the Great Depression lasted until the beginning of World War II.
The Great Depression had devastating effects in countries both rich and poor. Personal income, tax revenue, profits and prices dropped, while international trade plunged by more than 50%. Unemployment in the U.S. rose to 25% and in some countries rose as high as 33%.
Cities all around the world were hit hard, especially those dependent on heavy industry. Construction was virtually halted in many countries. Farming communities and rural areas suffered as crop prices fell by about 60%. Facing plummeting demand with few alternative sources of jobs, areas dependent on primary sector industries such as mining and logging suffered the most.
the Weimar Republic in Germany gave way to two episodes of political and economic turmoil, the first culminated in the German hyperinflation of 1923 and the failed Beer Hall Putsch of that same year. The second convulsion, brought on by the worldwide depression, resulted in the rise of Nazism. In Asia, Japan became an ever more assertive power, especially with regard to China.
Democracy and prosperity largely went together in the 1920s. The worldwide Great Depression that began in 1929 led to the collapse of democracy in most of Europe and the rise of expansionary dictatorships in Russia, Italy, Japan and Germany, as well as local dictatorships in Poland, Spain and elsewhere.
The changing world order that the war had brought about, in particular the growth of the United States and Japan as naval powers, and the rise of independence movements in India and Ireland, caused a major reassessment of British imperial policy. Forced to choose between alignment with the United States or Japan, Britain opted not to renew its Japanese alliance and instead signed the 1922 Washington Naval Treaty, where Britain accepted naval parity with the United States. The issue of the empire's security was a serious concern in Britain, as it was vital to the British pride its finance and its trade-oriented economy.
India strongly supported the Empire in the First World War. It expected a reward, but failed to get home rule as the Raj kept control in British hands and feared another rebellion like that of 1857. The Government of India Act 1919 failed to satisfy demand for independence. Mounting tension, particularly in the Punjab region, culminated in the Amritsar Massacre in 1919. Nationalism surged, and centered in the Congress Party led by Gandhi. In Britain public opinion was divided over the morality of the massacre, between those who saw it as having saved India from anarchy, and those who viewed it with revulsion.
Egypt had been under de facto British control since the 1880s, despite its nominal ownership by the Ottoman Empire. In 1922 it was granted formal independence, though it continued to be a client state following British guidance. Egypt joined the League of Nations. Egypt's King Faud and his son King Farouk, and their conservative allies, stayed in power with lavish life styles thanks to an informal alliance with Britain who would protect them from both secular and Muslim radicalism. Iraq, a British mandate since 1920, gained official independence in 1932 when King Faisal agreed to British terms of a military alliance and an assured flow of oil.
In Palestine, Britain was presented with the problem of mediating between the Arabs and increasing numbers of Jews. The 1917 Balfour Declaration, which had been incorporated into the terms of the mandate, stated that a national home for the Jewish people would be established in Palestine, and Jewish immigration allowed up to a limit that would be determined by the mandatory power. This led to increasing conflict with the Arab population, who openly revolted in 1936. As the threat of war with Germany increased during the 1930s, Britain judged the support of Arabs as more important than the establishment of a Jewish homeland, and shifted to a pro-Arab stance, limiting Jewish immigration and in turn triggering a Jewish insurgency. The Dominions (Canada, Newfoundland, Australia, New Zealand, South Africa and Ireland) were self governing and gained semi-independence in the World War. Britain still controlled foreign policy and defence. The right of the Dominions to set their own foreign policy was recognised in 1923 and formalised by the 1931 Statute of Westminster. Ireland effectively broke all ties with London in 1937.
French census statistics from 1931 show an imperial population, outside of France itself, of 64.3 million people living on 11.9 million square kilometers. Of the total population, 39.1 million lived in Africa and 24.5 million lived in Asia; 700,000 lived in the Caribbean area or islands in the South Pacific. The largest colonies were Indochina with 21.5 million (in five separate colonies), Algeria with 6.6 million, Morocco, with 5.4 million, and West Africa with 14.6 million in nine colonies. The total includes 1.9 million Europeans, and 350,000 "assimilated" natives.
A hallmark of the French colonial project from the late 19th century to the post-World War Two era the civilising mission (mission civilisatrice). The principle was that it was France's duty to bring civilisation to benighted peoples. As such, colonial officials undertook a policy of Franco-Europeanisation in French colonies, most notably French West Africa and Madagascar.
Catholicism was a major factor in the civilising mission, and many missionaries were sent. Often they operated schools and hospitals.  During the 19th century, French citizenship along with the right to elect a deputy to the French Chamber of Deputies was granted to the four old colonies of Guadeloupe, Martinique, Guyanne and Réunion as well as to the residents of the "Four Communes" in Senegal. Typically the elected deputies were white Frenchmen, although there were some blacks, such as the Senegalese Blaise Diagne, who was elected in 1914. Elsewhere, in the largest and most populous colonies, a strict separation between "sujets français" (all the natives) and "citoyens français" (all males of European extraction) with different rights and duties was maintained until 1946. French colonial law held that the granting of French citizenship to natives was a privilege and not a right. Two 1912 decrees dealing with French West Africa and French Equatorial Africa enumerated the conditions that a native had to meet in order to be granted French citizenship (they included speaking and writing French, earning a decent living and displaying good moral standards). For the 116 years from 1830 to 1946, only between 3,000 and 6,000 native Algerians were granted French citizenship. In French West Africa, outside of the Four Communes, there were 2,500 "citoyens indigènes" out of a total population of 15 million.
French conservatives had been denouncing the assimilationist policies as products of a dangerous liberal fantasy. In the Protectorate of Morocco, the French administration attempted to use urban planning and colonial education to prevent cultural mixing and to uphold the traditional society upon which the French depended for collaboration, with mixed results. After World War II, the segregationist approach modeled in Morocco had been discredited by its connections to Vichyism, and assimilationism enjoyed a brief renaissance.
Critics of French colonialism gained an international audience in the 1920s, and often used documentary reportage and access to agencies such as the League of Nations and the International Labor Organisation to make their protests heard. The main criticism was the high level of violence and suffering among the natives. Major critics included Albert Londres, Félicien Challaye, and Paul Monet, whose books and articles were widely read.
East Asia: Japanese dominance
Africa and Asia
- Aftermath of World War I
- Causes of World War II
- European Civil War
- International relations (1919-1939)
- Interwar Britain
- Jazz age
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