International relations in the 1930s
Learning Objectives:
Learn about the political impact of the Great Depression and the rise of dictatorships
Learn about the League of Nations’ inability to take effective action against aggression
Understand foreign polices adopted by Britain and France during the 1930s
Analyze why World War II broke out.
Between 1924 and 1929, international relations improved largely due to the USA’s economic strength.
American loans under the Dawes Plan helped ease tensions, leading to agreements like the Locarno Treaties. However, the 1929 Wall Street Crash triggered the Great Depression, causing mass unemployment, social unrest, and the rise of political extremism.
While Britain maintained democracy, countries like Italy, Germany, Spain, Japan, and the USSR saw the emergence of dictatorships under Mussolini, Hitler, Franco, military leaders, and Stalin.
These regimes pursued aggressive policies, isolating Soviet Russia and threatening global peace. The Spanish Civil War (1936–1939) highlighted the growing conflict between fascism, communism, and democracy.
How did the rise of extremism affect international relations?
Impact of the Great Depression on political ideologies
The US economy collapsed in 1929 due to overproduction, export dependence, and protectionist policies. As foreign demand for American goods fell, panic hit Wall Street, causing the stock market crash known as "Black Friday."
Banks failed, businesses collapsed, and unemployment soared, triggering the Great Depression.
Other countries, heavily reliant on American loans, were also affected. Germany's economy collapsed, disrupting reparations payments and further destabilizing Britain, France, and Italy.
As international trade declined, deflation and unemployment hit industrialized countries, causing social unrest and fueling political extremism.
Disillusioned with democratic governments, many turned to communism or fascism. While democracies like Britain, France, and the USA survived, weaker democracies in Germany, Japan, and Spain collapsed.
Adolf Hitler’s rise to power in Germany was closely tied to the impact of the Great Depression. Initially a struggling ex-soldier with limited prospects, Hitler gained attention through powerful speeches and became leader of the Nazi Party in 1921. Early Nazi support came mainly from unemployed youth and ex-soldiers, disillusioned by Germany’s post-WWI situation.
He criticized the democratic Weimar constitution, blamed politicians for the Treaty of Versailles, and warned of a communist threat. Although the Nazis attempted a failed uprising in 1923 (the Munich Putsch), Hitler’s popularity declined as Germany stabilized under the Dawes Plan and improved international relations.
However, the 1929 Wall Street Crash led to economic collapse and soaring unemployment in Germany. This renewed support for extremist parties, and by 1932 the Nazis became the largest party in the Reichstag. Hitler was legally appointed Chancellor in 1933 and quickly dismantled the democratic system, establishing a fascist, one-party dictatorship similar to Mussolini’s in Italy.
Impact of the rise of dictatorships on relations between powers
By 1933, four of the world’s leading nations – Italy, the USSR, Germany, and Japan – were governed by dictatorships through which the state controlled all aspects of life. These dictatorships maintained popular support by the extensive use of censorship and propaganda, crushing opposition through control over the armed forces. This clearly had an enormous impact on the lives of people living in those countries, but it also had an adverse effect on international relations. Tensions between the major powers, which had been gradually reduced during the 1920s, were renewed in the wake of the Great Depression and the establishment of dictatorships.
Nazism in Germany
Hitler’s rise to power alarmed many European countries. While Germany had improved international relations in the late 1920s—joining the League of Nations in 1926—Hitler’s aggressive nationalism and desire to overturn the Treaty of Versailles threatened this progress. France, fearing a rearmed Germany, returned to a tough stance, abandoning earlier efforts at cooperation.
Italy was also concerned, especially about Hitler’s plans to unite Germany and Austria. Mussolini supported Austria’s anti-Nazi government, even sending troops to the border in 1934 after Chancellor Dollfuss was murdered. This gained him praise from Britain and France.
The USSR saw Hitler as a major threat due to his anti-communism and his aim to expand eastward for Lebensraum(living space), as stated in Mein Kampf. Stalin tried to ally with Britain and France for protection, but both countries distrusted Soviet communism more than Hitler, especially amid their own political instability during the Great Depression.
Military dictatorship in Japan
The rise of dictatorships increased global tensions beyond Europe. In Japan, limited experience with democracy and growing poverty after the Wall Street Crash led to public disillusionment with elected leaders. In 1931, the Japanese army seized Manchuria without government approval, prompting the collapse of democracy and the rise of a military dictatorship under Emperor Hirohito.
Japan's aggressive expansion alarmed China and threatened Western interests. In 1933, Japan left the League of Nations and later abandoned disarmament agreements. In 1936, Japan and Nazi Germany signed the Anti-Comintern Pact to oppose communism, especially the USSR. Italy joined in 1937, forming a powerful alliance of three dictatorships with expansionist goals. This alliance deeply concerned Britain, France, the USA, and the USSR, with U.S. President Roosevelt warning it could be aimed at global domination.
Fascism in Italy
By 1934, Mussolini was respected internationally for his diplomacy, but at home, economic struggles and unmet promises hurt his popularity. Seeking a boost, he turned to aggressive foreign policy, inspired by Hitler’s successes. In 1935, Mussolini invaded Abyssinia, ignoring international criticism, except from Hitler’s Germany, which supported the move.
This marked a shift in Mussolini’s alliances: he abandoned ties with Britain and France and aligned with Nazi Germany. In 1936, they formed the Rome-Berlin Axis, followed by the Pact of Steel in 1939—a full military alliance. This alarmed other nations, especially the USSR, which tried to ally with Britain and France. However, fear and distrust of communism prevented any agreement.
By the late 1930s, the combination of economic crisis and aggressive dictatorships had dangerously destabilized global politics. Upcoming events in Spain would further expose these tensions.
Foreign responses to the civil war in Spain
In Spain, as in Germany and Japan, democracy collapsed under the pressure of the Great Depression. The country had been governed by King Alfonso XIII’s constitutional monarchy since 1885, but it was weak and divided. Multiple political groups emerged, each with different goals:
Monarchists supported the king and the Church, but were split between Bourbonists and Carlists.
Liberals wanted a modern democracy with reduced royal and Church power.
Socialists pushed for state control of industry and faster reforms.
Communists sought a revolution and a classless society.
Anarchists opposed all authority, favoring self-managed local communities.
Separatists wanted independence for regions like the Basque Country and Catalonia.
These deep divisions made stable democratic governance nearly impossible.
The Spanish Civil War, which began in 1936, was not the quick military takeover that Franco’s Nationalists had hoped for.
Resistance from anarchists and republican supporters, especially in Madrid and Barcelona, halted their advance. As the war intensified, Franco sought help from Hitler and Mussolini, who supported him to gain a potential fascist ally in southern Europe.
Germany and Italy sent troops and weapons, while Britain and France, fearing war with Germany, pushed for non-intervention. A League of Nations Non-Intervention Committee was formed, but Germany and Italy ignored it. The republicans, denied Western help, turned to the USSR.
By late 1936, the Spanish Civil War had become a wider ideological conflict between fascism and communism, deeply affecting international relations.
Italy, Germany, and the USSR each supported different sides in the Spanish Civil War for their own reasons.
Mussolini sought glory and used the war for propaganda, sending tens of thousands of troops. Hitler used the war to test German weapons and distract Mussolini from Austria, even supplying arms to both sides to prolong the conflict. Stalin backed the Republicans just enough to prevent a fascist victory but not enough to install a communist government, fearing British and French backlash.
The war drew in volunteers from across the world, many motivated by anti-fascism or economic hardship. Despite international claims of neutrality, Germany and Italy openly supported Franco’s Nationalists, while the League of Nations failed to act.
By 1939, with Soviet aid cut and more German support flowing in, Franco’s forces captured Barcelona and Madrid, securing victory. Franco established a repressive regime similar to Hitler's and Mussolini's, though he strongly supported the Catholic Church and avoided anti-Jewish policies. Spain remained neutral in WWII, and Franco ruled until 1975.
Aims and impact of Hitler’s expansionist policies
Hitler’s main foreign policy aims can be summarised as:
ending Germany’s commitment to the Treaty of Versailles
recovering all lost territory, including the Polish Corridor
developing the German army, navy, and air force
uniting all German-speaking people under the government of Germany, beginning by forming a union with Austria (Anschluss)
supporting the concept of Lebensraum, providing more ‘living space’ for the German people by the acquisition of more territory – initially popularised within Germany at the beginning of the 20th century, Lebensraum became a fundamental principle of Nazism in the 1930s
In March 1935, Hitler defied the Treaty of Versailles by reintroducing conscription and announcing the formation of the Luftwaffe, aiming to build Germany's military strength.
His actions prompted Britain, France, and Italy to form the Stresa Front, a weak alliance designed to prevent German rearmament and protect Austria. However, the agreement lacked clear action plans and did not mention Germany directly, making it ineffective.
In June 1935, Britain signed the Anglo-German Naval Agreement, allowing Germany to build a navy that violated the Treaty of Versailles, weakening the Stresa Front.
Meanwhile, in October 1935, Mussolini invaded Abyssinia, expecting no opposition from his allies. When Britain and France supported League of Nations sanctions against Italy, Mussolini withdrew from both the League and the Stresa Front. Despite these challenges, Hitler continued his rearmament plans unopposed.
Why did the League of Nations fail to keep the peace in the 1930s?
The failure of disarmament
The League of Nations failed to achieve its goal of disarmament, which was one of its key aims after World War I.
Despite optimism at the World Disarmament Conference in 1932, the conference collapsed due to several factors. The global economic depression of the late 1920s led many countries to maintain their armaments for security. Japan’s aggression in Manchuria and its subsequent withdrawal from the League further undermined disarmament efforts, as nations felt the need to protect themselves.
Hitler’s rise to power in 1933 also alarmed European countries, as he openly sought to dismantle the Treaty of Versailles and restore Germany’s military strength.
Hitler demanded that Germany be allowed to rearm, citing the unequal disarmament terms of the Treaty of Versailles, which he argued left Germany vulnerable. This request was unacceptable to France, which feared a resurgent Germany. As a result, Hitler withdrew Germany from both the Disarmament Conference and the League of Nations in October 1933, signaling the League's inability to prevent militarization or aggression.
Germany and Japan, two of the world’s major nations, were no longer members of the League, and both seemed committed to increasing their armaments. Interpreting this situation as a serious threat to their own national interests and security, the other major European countries and the USA felt the need to increase, rather than decrease, their armaments. As a result, the World Disarmament Conference broke up in disarray, having achieved none of its ambitious aims.
Reasons for and actions taken in response to the crises in Manchuria
In the 1920s, the League of Nations resolved minor disputes, but its weakness became clear when major powers were involved.
In 1931, Japan invaded Manchuria, threatening the interests of the USA and European powers. China appealed to the League, which ordered Japan to withdraw. Japan refused, prompting a League investigation led by Lord Lytton. The Lytton Report, published in 1932, found both sides at fault but recommended that Manchuria be returned to China. In 1933, the League voted to support the report, but Japan rejected the decision and continued its occupation.
The League was unable to act—Britain and France, weakened by the Great Depression, were unwilling to impose sanctions or go to war. Lacking support from its key members, the League failed to stop Japanese aggression.
Japanese invasion of China
In 1937, Japan invaded China, but the League of Nations offered only sympathy, not help.
Britain and France, struggling with the Great Depression and committed to appeasement, avoided conflict. Japan, having left the League and allied with Germany, faced no real opposition.
Throughout the 1930s, the League failed to stop aggression by Germany, Italy, and Japan, as its main powers, Britain and France, were unwilling to act.
Changing attitudes of the major powers towards the League of Nations
The League of Nations needed the full commitment of major powers to be effective, but during the 1930s, that commitment weakened. Italy, Germany, and Japan withdrew after defying League decisions, seeing it as a barrier to their ambitions. The USSR joined in 1934 out of concern over Germany and Japan, but remained critical of the League’s failures.
Britain and France, the League’s main powers, lost interest in enforcing its principles, prioritizing their own national interests and appeasement policies. Their weak response to Italy's invasion of Abyssinia exposed their reluctance to act. Economic hardship from the Great Depression and fear of another war further reduced their willingness to use military force.
As a result, the League failed to stop aggression and lost the trust of smaller nations that relied on it for security.
Why, and with what effects, did Britain and France pursue a policy of appeasement?
By 1938, Hitler had openly defied the Treaty of Versailles, remilitarized the Rhineland, annexed Austria, and built a powerful military—all without serious opposition.
Britain and France, committed to appeasement and wary of another war, allowed his actions to go unchecked. Hitler exploited their inaction and used diplomacy to divide them, such as at the Disarmament Conference and through the Anglo-German Naval Agreement.
Britain, in particular, saw a strong Germany as beneficial for trade and believed the Treaty of Versailles had been too harsh. Many British politicians viewed Hitler as addressing legitimate grievances and seeking peace, especially after his non-aggression pact with Poland and the peaceful reclaiming of the Saar. France, more fearful of Germany, was unwilling to act without British support.
This appeasement continued until 1939, when Germany's full takeover of Czechoslovakia made it clear that Hitler’s ambitions went beyond justice and peace.
The Nazi-Soviet Pact revealed that no alliance between Britain, France, and the USSR was possible, making war more likely. Hitler had already broken promises made at the Munich Conference by seizing all of Czechoslovakia, and now Poland faced an imminent threat.
Despite his generals' warnings, Hitler believed Britain and France would not act and launched a staged attack to justify invading Poland on 1 September 1939. Britain and France, unprepared but no longer willing to appease, declared war shortly after. Stalin also invaded eastern Poland on 17 September.
World War II
World War II (1939–1945) was a global conflict involving most of the world's nations, divided into two major alliances: the Allies (mainly Britain, France, the Soviet Union, China, and later the United States) and the Axis (primarily Germany, Italy, and Japan).
World War II began with the invasion of Poland, but its causes were complex. Key factors included:
German resentment over the Treaty of Versailles
The League of Nations’ failures
The global economic crisis
Fear of communism blocking alliances
Appeasement allowed Hitler to grow bold
The Nazi-Soviet Pact
Hitler’s unjustified invasions of Czechoslovakia and Poland
Rise of fascist dictatorships in Germany (Hitler), Italy (Mussolini), and Japan.
Major Events:
1939: Germany invaded Poland → Britain and France declared war.
1940: Germany conquered much of Western Europe.
1941: Hitler invaded the USSR; Japan attacked Pearl Harbor → the U.S. entered the war.
1942–43: Turning points at Stalingrad (USSR) and Midway (Pacific).
1944: D-Day – Allied invasion of Nazi-occupied France.
1945: Germany surrendered in May; atomic bombs were dropped on Hiroshima and Nagasaki in August → Japan surrendered.
Consequences:
Over 70 million deaths, widespread destruction.
Holocaust: genocide of 6 million Jews by the Nazis.
Formation of the United Nations to prevent future wars.
Start of the Cold War between the U.S. and USSR.
Decolonization: Many countries in Asia and Africa gained independence after the war.