By the late 1920s, Japan had something close to a working democracy: elected parties, a free press, and civilian prime ministers. Twenty years later, generals ran the country and Japan was fighting most of the world.
This section explains how that change happened — and why historians disagree about whether it was inevitable.
Cause and consequence: a slow takeover, not one event: There was no single coup that installed military rule in Japan. Instead, militarism grew step by step through the 1930s, as assassinations, economic crisis and army successes abroad each weakened civilian government a little more.
The Great Depression hit Japan hard from 1930. Silk exports — a huge part of the rural economy — collapsed, and farming families slid into desperate poverty.
Many ordinary Japanese, and many young army officers from rural backgrounds, blamed the crisis on party politicians and big business zaibatsu, who they saw as corrupt and too soft on the West.
- Assassinations and terror — nationalist and military extremists murdered several political and business leaders in the early 1930s, including finance minister Inoue Junnosuke (1932) and Prime Minister Inukai Tsuyoshi (May 1932), whose killing effectively ended party-led (civilian) cabinets — no elected-party politician served as prime minister again until after 1945.
- The February 26 (1936) coup attempt — around 1,400 young army officers, part of the radical 'Imperial Way' faction, seized central Tokyo, killed several senior ministers and tried to force a military-led government. The coup failed when the Emperor Hirohito personally ordered it crushed, but it terrified civilian politicians into giving the army almost anything it wanted afterwards.
- Result: government by intimidation — after 1936, cabinets were built around army and navy demands. Any minister who resisted risked assassination, so civilian control of policy — especially foreign and military policy — steadily disappeared.
It is worth noticing what did not happen: Japan never had a single dictator like Hitler or Mussolini. Power was shared and contested between army factions, the navy, and the cabinet, with the Emperor remaining head of state throughout.
This matters for essay arguments about how militarism took hold — it was less a personal seizure of power and more the army gaining an effective veto over government.
A key debate to use in your essay: Historians disagree on the main driver of militarism. One argument stresses economic desperation (Depression, rural poverty) pushing people toward radical solutions. Another stresses institutional weakness — Japan's constitution let the army and navy ministers resign and bring down a cabinet, giving the military structural leverage no matter the economic climate. A strong answer weighs both rather than picking only one.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it free for 7 days:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Japanese expansion was not only about what happened at home — it was driven by officers acting abroad, often without Tokyo's permission. Manchuria in 1931 is the clearest example.
The Mukden Incident and the invasion of Manchuria, 1931: On 18 September 1931, Japanese officers of the Kwantung Army (Japan's force guarding its railway rights in Manchuria) secretly blew up a small section of track near Mukden — then blamed it on Chinese saboteurs to justify a full invasion. This is a textbook case of a manufactured pretext.
1. The Kwantung Army acts alone
Officers on the ground invaded and occupied Manchuria without clear orders from the civilian government in Tokyo, which learned of the scale of the operation largely after the fact.
2. Manchukuo is created (1932)
Japan set up the puppet state of Manchukuo, installing the last Qing emperor, Puyi, as a figurehead ruler while Japanese officials actually controlled the administration, resources and army.
3. The League of Nations condemns it
The League's Lytton Report (1932) found Japan guilty of aggression. Japan responded in 1933 by walking out of the League entirely rather than reverse the conquest, showing the League could not enforce its rulings on a determined great power.
4. The army gains prestige at home
Manchuria's success (its coal, iron and farmland were valuable) made the army enormously popular in Japan and proved that acting first and asking permission later paid off — encouraging further unauthorised expansion.
Mukden → Manchukuo → League condemns, Japan quits → army's prestige soars.
Manchuria set a pattern: field officers created a crisis, Tokyo was presented with a fait accompli, and civilian leaders who might have restrained the army were sidelined or intimidated. This is why many historians treat 1931 — not 1937 or 1941 — as the true starting point of Japan's slide into war.
By the time Japan invaded China proper in 1937 and then moved into Southeast Asia from 1940–41, it needed a way to justify controlling other Asian peoples. The answer was the Greater East Asia Co-Prosperity Sphere, announced in 1940.
The official propaganda claim
- Japan was liberating Asia from Western imperialism (Britain, France, the Netherlands, the USA)
- 'Asia for the Asians' — shared prosperity under Japanese leadership
- A common defence against Western economic and military domination
- Modernisation and development brought to occupied territories
The reality on the ground
- Occupied Korea, Taiwan, Manchuria, China and later Southeast Asia were run for Japan's economic and military benefit
- Forced labour, requisitioned rice and raw materials, and brutal military rule were common
- Local nationalist movements were suppressed unless they served Japanese war aims
- The Sphere functioned as a Japanese empire in most practical respects, not a partnership
Use this contrast in essays about the Sphere: A strong Paper 3 answer on the Co-Prosperity Sphere does not just describe it — it evaluates the gap between the anti-colonial rhetoric and the extractive reality, and notes that some nationalists (e.g. in Burma, the Dutch East Indies) briefly welcomed Japan as anti-Western, before turning against harsh occupation.
Never wonder what to study next
Get a personalized daily plan based on your exam date, progress, and weak areas. We'll tell you exactly what to review each day.
By 1941 Japan was trapped by its own expansion. It needed oil and raw materials for its war in China, but the USA — alarmed by Japan's occupation of French Indochina — had cut off oil exports and frozen Japanese assets.
Why Pearl Harbor? A calculated gamble: Japan's leaders knew they could not win a long war against America's vastly larger industrial base. Admiral Yamamoto Isoroku's plan was to cripple the US Pacific Fleet in one surprise strike, buy time to seize resource-rich Southeast Asia (oil in the Dutch East Indies, rubber and tin in Malaya), and force a negotiated peace before America could rebuild.
On 7 December 1941, Japanese carrier aircraft attacked the US naval base at Pearl Harbor, Hawaii, sinking or damaging eight battleships and killing over 2,400 Americans. The attack achieved surprise, but it also brought the United States into the war fully united and furious — the opposite of what Japan needed.
- Rapid Japanese advance, 1941–42 — within months Japan seized the Philippines, Malaya, Singapore, Burma and the Dutch East Indies, creating a vast defensive perimeter across the Pacific and Southeast Asia.
- The turning point: Midway, June 1942 — US codebreakers learned of a planned Japanese attack on Midway Island; American carriers ambushed and sank four Japanese aircraft carriers, destroying Japan's ability to replace its best-trained pilots and ships.
- Island-hopping, 1943–45 — US forces fought back island by island (Guadalcanal, Iwo Jima, Okinawa), each battle bloodier than the last as Japanese defenders fought almost to the last man, foreshadowing the huge casualties an invasion of Japan itself would cost.
While soldiers fought overseas, life at home changed completely. The government mobilised the whole economy and population for total war.
| Home front measure | What it meant for ordinary Japanese |
|---|---|
| Rationing and shortages | Food, fuel and clothing were tightly rationed; by 1944–45 many civilians faced real hunger |
| Labour mobilisation | Students, women and colonial subjects (Korean, Chinese) were conscripted into factories and mines, often in brutal conditions |
| Propaganda and censorship | State media demanded sacrifice for the Emperor and hid the truth about military defeats |
| Firebombing of cities | From 1944 US B-29 bombers began mass raids; the Tokyo firebombing of 9–10 March 1945 alone killed around 100,000 people and destroyed much of the city |
By mid-1945, Japan's navy and air force were largely destroyed, its cities were being burned by nightly bombing raids, and it was clearly losing — yet its government would not surrender.
The atomic bombs and Soviet entry, August 1945: The USA dropped atomic bombs on Hiroshima (6 August) and Nagasaki (9 August 1945), killing well over 100,000 people combined, many instantly, with many more dying later from burns and radiation sickness. On 8 August the USSR declared war and invaded Japanese-held Manchuria, destroying Japan's last hope of a mediated peace through Moscow.
Emperor Hirohito announced Japan's surrender by radio on 15 August 1945 — the first time most Japanese had ever heard his voice. The formal surrender was signed aboard the USS Missouri on 2 September 1945, ending the Second World War.
The historical debate you must know: This is one of the most argued questions in modern history: why did Japan actually surrender — the atomic bombs, the Soviet invasion, or both together? One view says the bombs' shock was decisive. Another argues Soviet entry mattered just as much (or more), since it destroyed Japan's plan to use Moscow as a neutral mediator and opened a second front in Manchuria. A strong essay presents both factors and reaches a judgement rather than assuming the bombs alone explain it.