Nanshinron (Southward Advance Theory) (南進論)

The Nanshinron (southward advance) theory was one of Japan's foreign policies before World War II, advocating that the country should advance into Southeast Asia and the South Pacific islands.


Nanshinron was first advocated during the Meiji period. It was discussed in relation to Japan's colonial rule of Taiwan and her mandate over the Pacific islands after World War I. It was vigorously advocated especially during the Sino-Japanese War. It was not necessarily linked to Japan's territorial expansion and military advance in the Meiji period. After the 1930s it was associated with an idea of 'Self-sufficiency and Self-defence' in Japan.
It was geared into 'the southward advance of Japanese armies.'
It is also called 'the Hokushu Nanshin (defend the north and advance to the south) policy.'

Nanshinron in the Meiji and the Taisho Period

The Nanshinron theory was advocated by some civilian critics such as Ukitchi TAGUCHI, Shigetaka SHIGA and Sadakaze SUGANUMA. It was roughly divided into two: one branch deriving from free trade and the other from Asianism. The critics attempted trade with and immigration to islands in Oceania and Southeast Asia. Nanshinron during the Sino-Japanese War was a concrete claim over Japan's colonial rule of Taiwan. After the Wars with China and Russia, Japan's basic national policy became 'Hokushinron,' advance into Northeast Asia, including Korea, Manchuria and mainland China. Nanshinron therefore remained as a non-governmental and non-mainstream foreign policy. (When the Philippine Revolution took place after the Sino-Japanese War (in 1898), efforts were made for the Imperial Japanese Navy to support the revolutionaries in order to secure Japan's influence there. However, this was abandoned).

When Japan took part in World War I in 1914, the Imperial Japanese Navy conquered German Micronesia (South Pacific islands). After the war the islands practically became Japan's colony as her mandate. They were identified as 'Ura Nanyo,' i.e., the Japanese base to advance into 'Omote Nanyo' (the islands in Southeast Asia). Southward advancement became a fad. However, mainstream Nanshinron during this period advocated peaceful economic advance, focusing on trade, investment and immigration.

Nanshinron before World War II in the Showa Era

After the Manchurian Incident Japan was internationally isolated as her relationship with Britain and the United States worsened during the 1930s. 'Southward advance' was considered as one of the powerful options for Japan's prospective policy. It was argued that it had to be carried out even with military force.

Yet it was only in 1940 that military advance into the south was determined as a national policy. Japan was then dragged into the quagmire of the Sino-Japanese War. The German blitzkrieg operations during April to June 1940 made the Netherlands and France that had colonies in Southeast Asia surrender to Germany. Britain was also endangered.
Taking advantage of this situation, Japan believed that it could get out of the critical situation if she could make Southeast Asia a part of the country
Thus, she decided on military advancement to the south.

Rather than a carefully prepared national policy, this was the one to makeshift. On July 27 the Imperial General Headquarters-Government Liaison Conference decided that Japan was to advance towards Southeast Asia, if necessary, with military force.

Japan's first target was French Indochina. Indochina was then a support route of Britain and the United States to China under the Nationalist (Chiang Kai-sek) Government. In September 1940 the Japanese Imperial Navy advanced into Indochina according to an agreement with France. (Advancement into the northern part of French Indochina).

As a result, the United States banned the export of oil to Japan. Japan started a war with the United States. Japan's advance into the south caused her to lose the war.

Target Resources in Japan's Advance into the South
Mainland China
Flour, cotton, linen, coal, iron ore, bauxite and tungsten.
The American Philippines
Rice, flour, sugar, wood, tobacco, linen, poplar, coal, iron, steel, copper, lead, sulphur, chrome, molybdenum, gold and manganese.
French Indochina
Rice, corn, gum, jute, coal, zinc, tungsten.
British Borneo
Rice, sugar, tobacco, oil.
Dutch East India
Rice, corn, sugar, gum, copra, quinine, oil, coal, bauxite, nickel, tin and gold.
British Malaya
Sugar, cotton, gum, tobacco, coal, iron ore, tin, bauxite, tungsten.
Rice, sugar, wood, tobacco, iron ore, coal, tin, zinc, antimony, tungsten, manganese.
British Burma
Rice, flour, beans, tobacco, oil, coal, copper, tin, lead, zinc, tungsten, nickel, gold and silver.

[Original Japanese]