1The idea in one paragraph

Between 1931 and 1941 three states used force to overturn the order made after the First World War. Japan seized Manchuria in 1931, went to full-scale war with China in 1937, and in 1941, facing an American oil embargo, attacked the United States. Italy conquered Abyssinia in 1935–1936 and Albania in 1939, and joined the war in 1940. Germany tore up the Treaty of Versailles step by step from 1933, absorbed Austria and Czechoslovakia in 1938–1939, and invaded Poland in September 1939. Three kinds of cause run through all three: ideology (militarism, fascism, Nazism), economics (the Great Depression and the search for resources), and opportunity, created by weak neighbours and by a League of Nations whose leading members would not risk war to enforce collective security, the idea that all members would act together against an aggressor. The exam asks how much weight each cause carries, and why the responses failed.

2Japan: the causes of expansion

Nationalism and militarism. Modern Japan was built by the Meiji state around the emperor, the army and the idea that Japan must be strong to avoid being colonised. By 1931 Japan held Korea, Taiwan and railway rights in southern Manchuria, guarded by the Kwantung Army. Nationalists resented the West: the League had rejected Japan's proposal for a racial equality clause in 1919, the US had shut out Japanese immigrants in 1924, and the Washington naval treaty (1922) held Japan below Britain and the US. The army answered to the emperor, not the cabinet, and the army and navy ministers had to be generals and admirals (from 1936, serving ones), so the services could bring a government down by refusing to supply one. Junior officers influenced by ultranationalists believed politicians and businessmen were betraying the nation. Officers who acted on their own initiative, in Manchuria and at home, were rarely punished; historians call this pattern gekokujō, "the lower overturning the higher".

Political and economic issues at home. The Great Depression hit Japan hard. The American market for raw silk, the income of millions of farm households, collapsed, and rice prices fell; rural poverty fed support for the army, which recruited heavily from the countryside. Party governments looked weak and corrupt. Prime Minister Hamaguchi was shot in 1930 by a nationalist who blamed him for accepting the London Naval Treaty, and Prime Minister Inukai was murdered by naval officers in May 1932, after which party cabinets ended. An army rising in Tokyo on 26 February 1936 was crushed, but it left the army leadership stronger. Economically, Manchuria offered coal, iron, farmland and a protected market at a time when other powers were raising tariffs against Japanese goods. Japan depended on imports, above all American oil and scrap iron, and the military wanted an empire that could supply a long war.

Political instability in China. China was divided among warlords until the Guomindang (GMD) under Chiang Kai-shek set up a national government in Nanjing in 1928, and even then the GMD was fighting the Chinese Communist Party (CCP). Chiang's policy was to crush the Communists first and resist Japan afterwards. Chinese nationalism was rising, with boycotts of Japanese goods and plans to build railways competing with Japan's. For the Kwantung Army, China was weak enough to be pushed and strong enough to be dangerous later: the moment to act was now.

Figure 1 sets out the Japanese case study.

3Japan: the events

Manchuria and northern China (1931). On 18 September 1931 Kwantung Army officers, led by Ishiwara Kanji and Itagaki Seishirō, set off a small explosion on the South Manchurian Railway near Mukden and blamed Chinese soldiers. Without orders from Tokyo, the army occupied the main cities of Manchuria within months; the cabinet protested and then accepted it. Fighting spread to Shanghai in early 1932. In March 1932 the puppet state of Manchukuo was proclaimed, with Puyi, the last Qing emperor, as head. In 1933 the army took Jehol province, and the Tanggu Truce (May 1933) created a demilitarised zone south of the Great Wall; over the next two years Japan pressed into northern China.

The Sino-Japanese War (1937–1941). On 7 July 1937 a clash at the Marco Polo Bridge near Beijing escalated into full-scale war; Prime Minister Konoe Fumimaro sent reinforcements rather than settle. Shanghai fell after months of fighting, and the capital Nanjing was taken in December 1937, followed by weeks of mass killing and rape of civilians and prisoners; estimates of the dead range from tens of thousands to more than 200,000 and remain politically contested. In 1938 Japan took Wuhan and Guangzhou and Konoe proclaimed a "New Order in East Asia". The GMD retreated to Chongqing and would not surrender; the war became a costly stalemate. In 1939 Soviet forces under Zhukov defeated the Kwantung Army at Nomonhan, which turned Japanese planners away from the north and towards the resources of South-East Asia.

The Tripartite Pact, the outbreak of war, Pearl Harbor. After Germany's victories of 1940, the colonies of France and the Netherlands in South-East Asia looked undefended. Japan moved troops into northern French Indochina in September 1940 and signed the Tripartite Pact with Germany and Italy on 27 September 1940: each would help the others if attacked by a power not yet at war, a warning aimed at the US. A neutrality pact with the USSR followed in April 1941. When Japan occupied southern Indochina in July 1941, the US froze Japanese assets and cut off oil; Britain and the Netherlands followed. With oil stocks running down, an imperial conference decided on war unless diplomacy succeeded. Tojo Hideki became prime minister in October; the American terms of 26 November, the Hull note, demanded withdrawal from China and Indochina. On 7 December 1941 Japanese carrier aircraft attacked the US Pacific Fleet at Pearl Harbor, killing more than 2,400 Americans, while other forces struck Malaya, Hong Kong and the Philippines. Germany and Italy declared war on the US four days later, and the two wars became one.

4Japan: the responses

The League of Nations and the Lytton Report. China appealed to the League in September 1931. The League sent a commission under Lord Lytton, whose report (October 1932) found that Japan's action was not self-defence and that Manchukuo was not the product of a genuine independence movement, but also accepted that Japan had real interests in Manchuria and proposed an autonomous Manchuria under Chinese sovereignty. The Assembly adopted the report in February 1933 by 42 votes to 1, Japan voting against; the Japanese delegation walked out, and Japan announced its withdrawal from the League in March 1933. No sanctions followed. Britain and France had no forces to spare in the Far East and their own economies in crisis, and the US was not a member. When war came in 1937, the League condemned Japan and passed the matter to a conference in Brussels, which achieved nothing.

The Second United Front. In December 1936 Chiang was seized at Xi'an by his own general Zhang Xueliang, whose father had been killed by Japanese officers in 1928, and pressed to stop fighting the Communists and resist Japan. After the Marco Polo Bridge, the GMD and CCP formally agreed the Second United Front (September 1937); the Communist armies became nominally part of the national army. It kept China fighting, but it was a truce between enemies; after GMD forces attacked the Communist New Fourth Army in January 1941 it barely existed. China received Soviet aid from 1937 and American aid from 1938.

The international response and US–Japan tension. Figure 2 shows how American policy hardened.

The Stimson Doctrine (January 1932) refused to recognise Manchukuo: words without force. Roosevelt's "quarantine" speech of October 1937 hinted at collective action but led to none, and when Japanese aircraft sank the American gunboat Panay in December 1937 the US accepted an apology. The US Neutrality Acts of 1935–1937 reflected a public that wanted no war. From 1939 pressure became economic: notice to end the 1911 commercial treaty (July 1939), embargoes on aviation fuel and then scrap iron (1940), loans to China, and in July 1941 the freezing of assets and the end of oil. Britain, weaker, gave way under pressure in July 1940 and closed the Burma Road supply route to China for three months. Each American step was meant to deter Japan. Japanese leaders read them as a choice between giving up the empire in China and seizing the oil of the Dutch East Indies, which meant knocking out the US fleet first.

The historians. The Tokyo war crimes tribunal (1946–1948) described a long conspiracy for aggression. Later historians see less plan and more drift: Michael Barnhart stressed the military's search for economic self-sufficiency for a future total war, Louise Young showed how popular enthusiasm for Manchukuo pushed governments along, and Herbert Bix argued that Emperor Hirohito was more actively involved than the post-war picture allowed. Japanese nationalist writers still present 1941 as self-defence against encirclement.

5Germany and Italy: the causes of expansion

Fascism and Nazism. Mussolini, in power since 1922, preached that war was the test of a nation and promised a new Roman empire around the Mediterranean (mare nostrum, "our sea") and in Africa. Italy had also never forgotten its defeat by Ethiopia at Adwa in 1896, or the "mutilated victory" of 1919, when it gained less than it had been promised. Historians disagree about how consistent he was: Denis Mack Smith saw an opportunist and propagandist; MacGregor Knox argued that expansion abroad and revolution at home were a single programme. Hitler's aims, set out in Mein Kampf, went beyond revising Versailles: uniting all Germans in one state, then conquering Lebensraum ("living space") in the east from peoples he regarded as racially inferior, and destroying Bolshevism. A. J. P. Taylor (1961) argued that Hitler was an opportunist who exploited chances others handed him, much like earlier German statesmen; Hugh Trevor-Roper replied that the programme was there from the start, and Andreas Hillgruber described it as a plan in stages (Stufenplan).

Domestic economic issues. The Depression left Germany with about six million unemployed by early 1933. Rearmament and public works cut unemployment but created shortages of foreign currency and raw materials. In 1936 the Four-Year Plan, under Göring, set out to make the economy and army ready for war within four years, pushing for self-sufficiency (autarky). Tim Mason argued that by 1939 economic strain pushed Hitler into war sooner than he planned; Richard Overy disputed that the economy was in crisis enough to force the decision; Adam Tooze stressed Hitler's race against the growing economic power of Britain, France and above all the US. Italy's economy was weaker: the Depression, a state rescue of industry in 1933, and after 1935 an autarky imposed partly by sanctions. Abyssinia promised land for settlers and a distraction at home, and it drained the treasury; in 1939 Mussolini had to tell Hitler that Italy could not fight without vast supplies.

Changing alignments, the end of collective security, appeasement. In 1934 Italy was Germany's rival: when Austrian Nazis murdered the chancellor Dollfuss in July 1934, Mussolini sent troops to the Brenner Pass to protect Austria. In April 1935 Britain, France and Italy formed the Stresa Front against German rearmament. Within two months Britain undercut it with the Anglo-German Naval Agreement, and the Abyssinian crisis then drove Italy towards Germany: the Rome–Berlin Axis (1936), the Anti-Comintern Pact (Italy joined 1937), the Pact of Steel (1939). Collective security failed in Manchuria and died in Abyssinia; Belgium returned to neutrality in 1936, and the US stayed out under its Neutrality Acts. Into the gap came appeasement: the British, and more reluctantly French, policy of settling German grievances by negotiation and concession. Its reasons were real: memory of the Great War, public opinion, fear of bombing, a sense that Versailles had been too harsh, unready armed forces, an empire threatened by Japan and Italy as well as Germany, reluctant Dominions, and distrust of the USSR.

Figure 3 sets out the German and Italian case study.

6Germany and Italy: the events

German challenges to the post-war settlements (1933–1938). Germany left the Disarmament Conference and the League in October 1933, signed a non-aggression pact with Poland in 1934 to break France's eastern alliances, and saw the Saar vote to return in January 1935. In March 1935 Hitler announced an air force and conscription, both banned by Versailles. On 7 March 1936 troops re-entered the demilitarised Rhineland, breaking both Versailles and the Locarno treaties. At a meeting in November 1937, recorded in the Hossbach Memorandum, Hitler told his commanders that Germany must expand, starting with Austria and Czechoslovakia; Taylor doubted its importance as evidence of a plan. In March 1938 German troops entered Austria (the Anschluss), which a plebiscite endorsed.

Italian expansion. After a clash at the Walwal oasis in December 1934, Italy invaded Abyssinia on 3 October 1935, using aircraft and poison gas against Ethiopian forces, and took Addis Ababa in May 1936. In 1936–1939 Italian troops fought for Franco in Spain. On 7 April 1939 Italy invaded Albania, already an Italian client state, and annexed it. When Germany invaded Poland, Italy declared itself "non-belligerent". Only when France was collapsing did Mussolini declare war on Britain and France, on 10 June 1940; his attack on France in the Alps made little progress, and his invasions of British-held Egypt (September 1940) and Greece (October 1940) went badly.

German expansion (1938–1939) and the outbreak of war. Hitler then demanded the Sudetenland, the German-speaking border region of Czechoslovakia. At Munich on 29–30 September 1938 Chamberlain, Daladier, Mussolini and Hitler agreed its transfer; neither Czechoslovakia nor the USSR was present. On 15 March 1939 Germany occupied the rest of Bohemia and Moravia, the first seizure of non-German land, and Memel a week later. Britain and France guaranteed Poland on 31 March. Germany and Italy signed the Pact of Steel (22 May 1939), a full military alliance. Anglo-French talks with the USSR moved slowly, and on 23 August 1939 the Nazi–Soviet Pact stunned Europe: a non-aggression treaty with a secret protocol dividing Poland and eastern Europe. Germany invaded Poland on 1 September; Britain and France declared war on 3 September; the USSR invaded from the east on 17 September. In 1940 Germany took Denmark and Norway (April), then the Low Countries and France (May–June).

7Germany and Italy: the responses

To German aggression (1933–1938). Protest without action. Britain accepted rearmament and signed the naval agreement; France, divided and in an election campaign, would not act alone over the Rhineland, and Britain would not act with it. The Anschluss was accepted. Munich was the peak of appeasement: Chamberlain returned promising "peace for our time", and was cheered. France's alliance with Czechoslovakia was abandoned. The USSR, a League member from 1934 with pacts with France and Czechoslovakia, was left out, which fed Stalin's suspicion that the West wanted Hitler to turn east.

To Italian aggression (1935–1936). The League named Italy the aggressor within days and imposed sanctions, but not on oil, coal or steel, and Britain left the Suez Canal open to Italian shipping. Britain and France wanted to keep Italy as an ally against Germany, and in December 1935 their foreign ministers produced the Hoare–Laval Plan, which would have given Italy much of Abyssinia; its leak caused a public outcry and Hoare resigned. In June 1936 the Emperor Haile Selassie appealed in person to the League; in July the sanctions were lifted. Collective security had failed its test, and Italy had moved into Germany's orbit.

To German and Italian aggression (1940). Britain, led from 10 May 1940 by Winston Churchill, chose to fight on alone after the fall of France, evacuated its army from Dunkirk, and won the Battle of Britain. It struck back at Italy by sea at Taranto (November 1940) and on land in North Africa (December 1940), while the Greeks threw the Italian invasion back into Albania. The US moved from neutrality towards support: Roosevelt condemned Italy's entry in June 1940 as a stab in the back, traded destroyers for British bases (September 1940), introduced peacetime conscription and promised to be the "arsenal of democracy". The USSR used its pact with Germany to annex the Baltic states and part of Romania in June 1940. Vichy France accepted defeat and collaboration.

The historians on appeasement. Guilty Men (1940), written under a pseudonym by three journalists, blamed Chamberlain and his colleagues for weakness and blindness. Once the government papers opened, revisionists argued that appeasement was a rational response to real limits; John Charmley defended Chamberlain strongly. R. A. C. Parker replied that there were alternatives, above all a firm alliance with France and the USSR, and that Chamberlain chose not to take them.