Imperial Japan: Empire, War and Postwar Rebuild

In 1905, an Asian country beat a European empire in a major war. Forty years later, two atomic bombs fell on its cities. Within decades, it rebuilt itself into a leading economy. That country was Japan.

In this lesson, we follow Japan’s rise as an empire, its defeat in 1945 and its rebuilding. We see the army’s power, the debate between West and tradition, and the postwar “miracle”. We also see the price the environment paid.

1How did Japan become an empire?

The Meiji Constitution was proclaimed on 11 February 1889. It took effect on 29 November 1890. It created an elected Diet. But only about 1.1 percent of the people could vote for it.

The army and navy stood apart from civilian rule. Article 11 gave the emperor supreme command of both. The military could report to the emperor and bypass the civilian chain.

Japan then grew by war. It defeated China in 1894-95. In the Treaty of Shimonoseki, China ceded Taiwan to Japan. In 1905, Japan won the Russo-Japanese War. The Treaty of Portsmouth was signed on 5 September 1905. In 1910, Japan formally annexed Korea. That ended the Joseon dynasty.

• 1889-1890: Meiji Constitution. Only about 1.1% could vote.
• Article 11: the emperor commanded the army and navy.
• 1895: Taiwan ceded. 1905: victory over Russia. 1910: Korea annexed.

2Should Japan copy the West or stay itself?

Japanese thinkers argued about this. Fukuzawa Yukichi wrote “Datsu-A Ron”, meaning “Leaving Asia”, in 1885. He wanted Japan to join the “civilised” West and step away from its Asian neighbours.

Others wanted pride in Japan’s own values. One was the philosopher Miyake Setsurei. He said each nation should build on its own character.

• Fukuzawa Yukichi, 1885: “Leaving Asia“.
• Miyake Setsurei: build on Japan’s own values.

3How did the war end?

Japan’s war in China widened into the Second World War. On 7 December 1941, Japan attacked the US fleet at Pearl Harbor in Hawaii. The United States declared war the next day.

In August 1945, the United States dropped atomic bombs on two cities. Hiroshima was hit on 6 August and Nagasaki on 9 August. The Hiroshima bomb, “Little Boy”, used enriched uranium. The Nagasaki bomb, “Fat Man”, used plutonium.

Japan announced its surrender on 15 August. The formal surrender was on 2 September 1945. Japan’s empire was over.

• 7 December 1941: Pearl Harbor.
• 6 August: Hiroshima (uranium). 9 August: Nagasaki (plutonium).
• 15 August: surrender announced. 2 September 1945: formal surrender.

4What changed under the occupation?

The Allied occupation lasted until 28 April 1952. It was led by the United States, with General Douglas MacArthur as Supreme Commander. A new constitution took effect in 1947.

Article 9 of that constitution renounces war as a sovereign right. The first postwar election with no distinction of sex was held in 1946. That was the first time Japanese women voted. Universal suffrage was fixed in law in 1947.

• Occupation until 28 April 1952. Leader: MacArthur.
• 1947 constitution. Article 9 renounces war.
• 1946: women vote for the first time.

5What was the postwar miracle?

Japan’s growth is called an “economic miracle”. It is usually dated from 1955 to the oil crisis of 1973. In that time, Japan became the world’s third-largest economy.

It was not a pure miracle. Japan had built industry from the late nineteenth century. The Korean War, from 1950, helped the early recovery. The Tokaido Shinkansen began service on 1 October 1964. The Tokyo Olympics opened nine days later, on 10 October.

• Boom: 1955 to 1973. Japan became third-largest economy.
• Roots in earlier industry. The Korean War helped recovery.
• 1 October 1964: Shinkansen. 10 October: Tokyo Olympics.

6What did growth cost?

Japan’s first major pollution disaster came at the Ashio copper mine. It began in the 1880s. Tanaka Shozo spoke up for farmers along the Watarase River. The 1897 Mine Pollution Prevention Order followed.

Minamata disease was found in 1956 in Minamata, Kumamoto Prefecture. The cause was methylmercury in factory waste from the Chisso Corporation. Dumping ran from 1932 to 1968. Later, courts and settlements forced payments to victims.

A separate case was Itai-itai disease in Toyama. That was cadmium poisoning. Do not mix it with Minamata.

• Ashio: first major pollution disaster, 1880s. Tanaka Shozo led the farmers’ cause.
• Minamata: mercury, found 1956.
• Itai-itai: cadmium, Toyama.

7How does the story connect to today?

Many of these debates still matter. People argue over Article 9 and Japan’s role in Asia. Others study how rapid growth shaped cities and rivers. The same Hiroshima dome now stands as a memorial.

For exam work, link each event to a place. Hiroshima is on Honshu, Japan’s largest island. Nagasaki is on Kyushu. Taiwan and Korea were taken at different times, in 1895 and 1910.

• Hiroshima: Honshu. Nagasaki: Kyushu.
• Taiwan 1895, Korea 1910.

8What are the exam traps?

• Hiroshima is on Honshu. Nagasaki is on Kyushu. Different islands (Source: CAPF (ACs) 2025, Q85).
• Taiwan (1895) came before Korea (1910).
• Minamata is mercury. Itai-itai is cadmium.
• Hiroshima used uranium. Nagasaki used plutonium.
• Formal surrender: 2 September. Announcement: 15 August.