Welcome to International History: 1870–1945!
Hi there! This period is incredibly important because it covers the rise of global empires, the catastrophic world wars, and the first major attempts to create international peace (like the League of Nations). This study guide breaks down the complex events into clear, manageable chunks, ensuring you nail your AS Level Papers 1 and 2.
Don't worry if this seems like a lot of dates and places—we will use simple language, helpful acronyms, and real-world connections to make sure everything sticks!
Focus Period: 1870–1945 (The transition from imperial dominance to global conflict).
Part 1: Empire and the Emergence of World Powers (1870–1919)
Why was imperialism a significant force for late nineteenth-century Europe?
In the late 1800s, Europe experienced a second, more intense wave of colonization called New Imperialism. This wasn't just about trade; it was about political prestige and total control over territory.
Key Motives for Imperial Expansion (The 4 P's)
- Political Motives: Owning an empire was a sign of national strength and prestige. If Britain had colonies, France and Germany needed them too.
- Economic Motives: Europe needed new markets to sell the goods made during the Industrial Revolution and new sources for cheap raw materials (like rubber, oil, and minerals).
- Prestige/Status: Leaders believed that large empires meant global respect.
- Population/Social: Ideas of racial superiority (social Darwinism) were common, leading to the belief that Europeans had a duty to 'civilize' other parts of the world (the 'White Man's Burden').
The "Scramble for Africa"
This was the rapid takeover and division of African territory by European powers, mostly between 1881 and 1914. It was ruthless and often resulted in immense suffering for the local populations.
Did you know? In 1870, only 10% of Africa was under European control. By 1914, this figure was nearly 90%.
What was the impact of imperial expansion on international relations?
Imperial competition didn't always lead to open war in Europe, but it caused massive tension and rivalry.
Key Disputes and Tensions:
- The Berlin Conference (1884–85): Organized by Bismarck (Germany), this was an attempt by European powers to draw up rules for colonizing Africa peacefully. It showed that the powers were willing to cooperate to avoid European war, but they did so by carving up Africa without any African input.
- China Disputes (Boxer Rebellion): European powers tried to gain control and influence in China, leading to the Boxer Rebellion (1899–1901), where Chinese nationalists fought against foreign influence. International forces (including the USA and Japan) had to cooperate to crush the revolt, highlighting China's weakness and the global nature of imperialism.
- Tension over South Africa: Britain fought the Boers (Dutch settlers) in the Boer War (1899-1902). Germany openly supported the Boers, severely straining relations between Britain and Germany.
Key Takeaway for Imperialism: Imperialism shifted European rivalry onto a global stage, draining wealth from non-European areas and heightening geopolitical tensions that contributed to future wars.
Why did Japan and the USA emerge as world powers?
The Rise of Japan
Japan underwent incredibly rapid modernisation and military development starting with the Meiji Restoration (1868). They quickly adopted Western technology and industrialization.
- Wars and Recognition: Japan demonstrated its new power by defeating China in the Sino-Japanese War (1894–95) and, astonishingly, defeating Russia in the Russo-Japanese War (1904–05).
- Treaty with Britain (1902): The Anglo-Japanese Treaty recognised Japan as a major power, ending Japan's isolation.
- WWI Role: Japan joined the Allies, seizing German territories in China and the Pacific. By 1918, Japan was fully established as a major global power.
The Rise of the USA
The USA focused primarily on domestic expansion until the late 19th century (the 'closing of the frontier').
- Economic Growth: Massive industrial growth created a need for international markets and trade.
- Spanish-American War (1898): This short, successful war gave the US control over former Spanish colonies (Puerto Rico, Guam, the Philippines), officially marking its entry as an imperial power.
- WWI Entry: The USA eventually joined WWI in 1917. President Wilson's key role in the subsequent peace settlement confirmed the USA's position as a global political and economic leader.
Part 2: The League of Nations and International Relations in the 1920s
Why was there dissatisfaction with the peace settlements of 1919–20?
The peace treaties signed after World War I (e.g., Versailles, Trianon, Neuilly) were supposed to ensure lasting peace, but they immediately caused bitterness and instability.
Key Problems:
- Harsh Terms (Germany's 'Diktat'): Germany was forced to accept the War Guilt Clause (Article 231) and pay enormous reparations. They felt the treaty was a "dictated peace," causing deep resentment.
- Treaties and Implications: The Treaty of Versailles (Germany), Treaty of Sèvres (Turkey), Treaty of Saint-Germain (Austria), etc., stripped defeated powers of territory and resources.
- Successor States: New nations created in Eastern Europe (e.g., Czechoslovakia, Yugoslavia) contained diverse ethnic groups, leading to internal political friction and instability.
How and why did international tensions remain high (1920–23)?
The immediate post-war years were marred by economic chaos and lingering animosity.
Crises and Tensions:
- Ruhr Crisis (1923): When Germany defaulted on reparation payments, France and Belgium invaded the Ruhr region (Germany's industrial heartland) to seize resources directly. This led to German resistance, hyperinflation, and increased global instability.
- German Hyperinflation: The crisis resulted in the complete collapse of the German currency, destroying the savings of the middle class and radicalizing many against the Weimar Republic.
- Corfu Incident (1923): An Italian official was murdered in Greece. Mussolini (Italy) demanded compensation and invaded the Greek island of Corfu. The League of Nations failed to stop Mussolini effectively, showing its weakness early on.
Attempts at Improvement (Conferences): Despite the crises, attempts were made to stabilize relations, such as the Washington Conference (1921–22), which limited the naval power of major nations.
How successful were attempts to improve international relations from 1924–29?
The mid-1920s are often called the "Golden Age" for peace, driven primarily by US money and improved trust.
Steps Towards Stability:
- Dawes Plan (1924): The US stepped in to reschedule Germany's reparation payments and provided loans to stabilize its economy. This calmed the situation after the Ruhr Crisis.
- Locarno Treaties (1925): Germany voluntarily agreed to accept its western borders (with France and Belgium). This was a major diplomatic success, demonstrating mutual respect.
- Kellogg-Briand Pact (1928): Signed by 65 nations, this pact officially "outlawed war" as an instrument of national policy. While it lacked any mechanism for enforcement, it was a huge symbol of international goodwill.
The League of Nations in the 1920s:
The League had key structures (Assembly, Council, Agencies) and relied on Collective Security (the idea that all members would unite to stop any aggressor).
- Disputes Solved: The League was successful in smaller disputes, such as the Aaland Islands (1921) and Upper Silesia (1921).
- Agencies Success: Its Agencies (focused on health, labour, and refugees) did valuable humanitarian work.
- Weaknesses: Crucially, the USA never joined, and the League had no military force of its own. It relied on the goodwill of its members, which quickly eroded when bigger powers were involved (like the Corfu Incident).
Key Takeaway for the 1920s: The decade started with extreme tension (Ruhr, reparations) but settled into a period of cautious optimism, primarily thanks to US financial intervention and symbolic treaties like Locarno. The League excelled at minor issues but avoided major confrontations.
Part 3: The League of Nations and International Relations in the 1930s
How did the rise of extremism affect international relations?
The Great Depression (1929) devastated the global economy. Poverty and unemployment made radical political ideologies, like Fascism and Communism, much more appealing.
Impact of Dictatorships:
- Hitler (Germany) and Mussolini (Italy): These leaders believed in aggressive expansion and rejected the peaceful principles of the League of Nations and the Treaty of Versailles.
- Rearmament: Hitler’s policies, starting with Rearmament (openly defying Versailles), immediately increased tensions.
- Remilitarisation of the Rhineland (1936): Hitler marched troops into the demilitarized zone. Britain and France took no action.
- Expansionism: Hitler pursued the policy of Lebensraum (living space):
- Anschluss (1938): Union with Austria.
- Sudetenland (1938): Demanded German-speaking part of Czechoslovakia.
- Czechoslovakia (1939): Took the rest of the country.
- Spanish Civil War: Germany and Italy actively supported Fascist forces (Franco), using the conflict as a proving ground for their military machines (e.g., the bombing of Guernica).
Why did the League of Nations fail to keep the peace in the 1930s?
The League collapsed when faced with aggressors determined to ignore international law, particularly Japan and Italy.
Key Failures:
- Manchuria Crisis (1931–33): Japan invaded the Chinese region of Manchuria. The League took a year to condemn Japan and suggested a compromise. Japan simply withdrew from the League in 1933. The League was powerless because major powers (like Britain and France) were unwilling to risk conflict or major trade restrictions.
- Abyssinia Crisis (1935–36): Mussolini invaded Abyssinia (Ethiopia). The League imposed weak economic sanctions (they didn't ban oil sales or close the Suez Canal). This allowed Mussolini to complete his conquest. This event destroyed the concept of collective security.
- Changing Attitudes: Major powers like Britain and France prioritised national interests and domestic economic recovery over strengthening the League.
Why, and with what effects, did Britain and France pursue a policy of appeasement?
Appeasement was the policy of giving Hitler what he wanted in the hopes that he would be satisfied and prevent war.
Reasons for Appeasement:
- Economic Considerations: Britain and France were still recovering from the Great Depression and could not afford a major war or massive rearmament.
- Military Considerations: They needed time to rearm; their militaries were weaker than Germany's growing strength.
- Public Opinion: The public (especially in Britain) strongly favoured peace (following the horrors of WWI).
- Treaty of Versailles Guilt: Some leaders felt Germany had been treated too harshly in 1919 and Hitler's demands (like the Anschluss) were reasonable corrections.
Key Effects:
- Munich Crisis (1938): Britain and France agreed to let Hitler take the Sudetenland in exchange for a promise of no further expansion. This was the high point of appeasement.
- Result: Appeasement gave Hitler confidence that Britain and France were weak, allowing him to grow stronger and continue his expansion until he demanded Poland.
Why did war break out in 1939?
The final steps towards war happened quickly after the failure of appeasement.
- End of Appeasement: When Hitler took all of Czechoslovakia in March 1939 (breaking the Munich promise), Britain realized he could not be trusted. Britain issued a guarantee to Poland, promising to fight if Poland were invaded.
- The Nazi-Soviet Pact (August 1939): Germany and the USSR signed a non-aggression pact, shocking the world. This agreement meant Hitler did not have to worry about fighting a war on two fronts (East and West) when he invaded Poland.
- Invasion of Poland (September 1939): Germany invaded Poland. Britain and France, honouring their guarantee, declared war.
Key Takeaway for the 1930s: The Great Depression provided the political climate for aggressive dictatorships to rise. The League failed because members refused to back collective security with military force, leading Britain and France to choose appeasement. This policy ultimately failed, leading directly to WWII.
Part 4: China and Japan (1912–1945)
What were the implications of the 'warlord era' which affected China (1916–27)?
After the fall of the Qing Dynasty in 1912, China lacked a strong central government, leading to years of chaos.
The Warlord Era (1916–1927):
- Disintegration: China fragmented into regions ruled by Warlords—local military commanders who fought each other for power, resources, and taxes. This caused immense instability and suffering for the population.
- May the Fourth Movement (1919): A massive protest by students and intellectuals against foreign influence and the weak Chinese government after the Paris Peace Settlements (where Japan received former German territories in China). This boosted Chinese nationalism.
The Kuomintang (KMT) and Sun Yat-sen:
The Kuomintang (KMT) or Nationalist Party, led by Sun Yat-sen, aimed to unify China based on the Three Principles: nationalism, democracy, and people's livelihood.
- Northern Expedition (1926–28): Chiang Kai-shek took leadership of the KMT after Sun Yat-sen's death. He launched a massive military campaign to defeat the Warlords and unify China.
How effectively did Chiang Kai-shek deal with the communists (1927–36)?
The KMT and the Chinese Communist Party (CCP), initially allies, became bitter enemies.
Chiang’s Anti-Communist Actions:
- Shanghai Massacre (1927): Chiang launched a brutal attack on the CCP in Shanghai, effectively driving the Communists underground and starting a bloody Civil War.
- Extermination Campaigns: Chiang launched multiple military campaigns aimed at wiping out the CCP base, led by Mao Zedong, in the Jiangxi Soviet.
- The Long March (1934–35): Forced to flee Chiang’s campaigns, the CCP leadership and remaining troops undertook a 6,000-mile retreat. While devastating in terms of lives lost, the March was crucial because it cemented Mao Zedong's leadership and allowed the CCP to survive and establish a new base in Yan'an.
- The Xi'an Incident (1936): Chiang was kidnapped by one of his own generals and forced to agree to stop fighting the CCP and instead focus on fighting the greater threat: Japan.
Why did the CCP gain support up to 1945?
Despite KMT efforts, the CCP managed to grow its base, primarily among the peasant population.
- Land Reform: In the Yan'an Soviet, Mao introduced revolutionary land policies, taking land from wealthy landlords and giving it to the poor peasantry. This gained massive peasant support.
- War with Japan (after 1937): When Japan invaded, the CCP gained popularity by actively fighting the Japanese forces (especially through guerrilla warfare), while the KMT was often viewed as corrupt and ineffective in defending China.
- Unpopularity of the KMT: Chiang's government was plagued by inflation, corruption, and a focus on fighting the CCP rather than the Japanese invaders.
Why did Japan become a military dictatorship in the 1930s and with what consequences?
Japan had a brief period of democracy, but it failed due to economic crises and nationalist ambition.
Failure of Democracy:
- Dissatisfaction with Peace Settlements: Japan felt insulted by the treatment it received at the Paris Peace Settlements (1919), feeding nationalist sentiment.
- Economic Factors: The Great Depression hit Japan hard, leading to huge unemployment. The civilian government was blamed for not protecting Japan's economy.
Implications of Military Rule:
- Expansionism: Military leaders argued that Japan needed to conquer new territory (especially China's resources) to solve its economic problems and secure its survival. This belief fueled aggressive expansionism.
- Involvement in WWII: Japan's aggressive military foreign policy (invasion of Manchuria 1931, full-scale invasion of China 1937) directly led to confrontation with the Western powers (USA, Britain), culminating in its decision to join the Axis Powers in World War II.
Quick Review Box
Need a way to remember the rise of the aggressive powers? Think JIG:
- Japan (Manchuria 1931)
- Italy (Abyssinia 1935)
- Germany (Rhineland 1936 onwards)
The failure to stop any of these early aggressions guaranteed the eventual failure of the League of Nations and the start of WWII.