Imperial Japan's ambitious concept of a 'Greater East Asia Co-Prosperity Sphere'
By the late 1930s, Japan’s leaders increasingly promoted a regional order that claimed to free Asia from European imperialism, but instead advanced their own territorial control over its neighbours.
Framed as the “Greater East Asia Co-Prosperity Sphere,” the policy offered promises of unity and liberation while concealing the system of resource extraction and political control that was backed by military force.
With aggressive campaigns across China and Southeast Asia, as well as the Pacific, Japan built this vision into its wartime strategy, and it relied on propaganda to disguise conquest as cooperation.
Why the concept was developed
After Japan had achieved victory in the Russo-Japanese War of 1904–1905, military leaders and nationalist intellectuals argued that Japan had a supposed duty to lead Asia against Western exploitation.
Over the next two decades, that belief gradually hardened into a strategic goal.
Nationalist publications and military planning documents operated alongside government speeches and increasingly called for an Asia liberated from European rule but united under Japanese guidance.
The annexation of Korea in 1910 was the beginning of this imperial drive, which later expanded into the occupation of Manchuria in 1931 and the full-scale invasion of China in 1937.
Eventually, theorists within the Japanese government and armed forces began to develop what they described as a detailed plan for regional self-sufficiency that they often described in terms of Asian cooperation but that was grounded in Japanese control over trade and industry, along with regional security.
Key figures such as Ishiwara Kanji and General Araki Sadao promoted the idea that Japan's spiritual strength and military might supposedly entitled it to reshape Asia.
Officials insisted that Japan’s military strength gave it, in their view, the right to guide weaker nations toward independence.
At the same time, military victories created opportunities to build a regional group of countries that could resist Western sanctions and supply Japan with the raw materials it lacked.
The writings of thinkers like Kita Ikki included his 1919 tract "An Outline Plan for the Reorganisation of Japan" and influenced this ideological development, while documents such as the forged Tanaka Memorial were widely believed to have originated as anti-Japanese propaganda in China during the 1920s.
They were nonetheless used by the Allies to support accusations of Japanese imperial planning.
Formal declaration and propaganda
In June 1940, Foreign Minister Hachirō Arita publicly introduced the phrase “Greater East Asia Co-Prosperity Sphere,” which described a regional alliance where Japan would guide its neighbours toward shared development and security.
Japanese planners claimed that this vision would ultimately liberate colonised peoples and replace Western control with Asian cooperation.
To spread this message, officials launched a large and carefully planned propaganda campaign that included posters, films, songs, and schoolbooks, and all of these presented Japan as a helpful leader who lifted Asia out of foreign control.
To justify their actions, propagandists depicted the United States and Britain as foreign powers who had, they claimed, robbed Asia for centuries, while Japanese forces were presented as rescuers who restored local dignity.
Across the empire, Japan framed its occupation policies as part of a civilising mission, but many of those who lived under Japanese rule experienced strict limits on their freedoms and heavy labour demands under widespread surveillance.
Japan used cultural tools such as the 1943 film "The Opium War" to paint Britain as the historical enemy of Asia.
Also, the regime showcased the Greater East Asia Conference in Tokyo in November 1943, which featured only puppet or collaborationist governments, to promote a false picture of pan-Asian unity.
Rather than receiving support for local development, most territories faced economic damage and military repression.
Military conquests and occupation
After Japan had launched the attack on Pearl Harbor in December 1941, Japan moved rapidly to seize colonial possessions across Southeast Asia and the Pacific.
Within months, its forces controlled French Indochina, the Dutch East Indies, the Philippines, British Malaya, Singapore, and Burma.
Japanese commanders claimed in their public statements that these invasions aimed to remove European influence and return power to local peoples.
In reality, the new regimes operated under Japanese military control and demanded obedience to Tokyo’s central authority.
To pretend that it allowed local independence, Japan established puppet governments in several occupied regions.
In the Philippines, José P. Laurel became president of a republic in name only in 1943, while Ba Maw headed a similar regime in Burma.
Indonesian leaders Sukarno and Mohammad Hatta cooperated with Japanese officials because they believed that they could use the occupation to prepare for real independence.
However, Japan retained control over all major decisions and used these administrations to extract resources and to suppress dissent so that they controlled local populations more tightly.
Security forces often arrested suspected resisters, executed suspected informants, and enforced loyalty through threats and intimidation.
In occupied Thailand, the government signed a treaty of alliance with Japan in December 1941, and construction of the Burma Railway began in June 1942 and relied on forced labour, which included Allied prisoners of war and Asian civilian labourers under deadly conditions.
Economic and political control
Japan’s wartime economy demanded steady access to oil, rubber, rice, metals, and industrial labour, all of which it took from the occupied territories through carefully planned policies that took resources.
Under orders from military headquarters, regional commanders confiscated plantations, seized mines, and redirected agricultural output to support the Japanese war machine.
In Vietnam, the seizure of rice reserves, coupled with severe flooding, typhoons, hoarding, and Allied bombing of transport routes, triggered a famine in 1945 that, by some estimates, killed up to two million people.
To manage local economies, Japan replaced currencies with military-issued notes, which triggered very high inflation, and it forced local businesses to follow centrally dictated production plans.
In many regions, economic trouble worsened as forced labour increased and access to basic goods disappeared.
Daily life under the Co-Prosperity Sphere often involved food shortages, curfews, public beatings, and forced moves.
Japan relied on military rule to enforce its economic goals, and local populations paid the price with hunger and a loss of freedom, which created widespread fear.
In Indonesia, the Japanese implemented the Romusha system, which conscripted millions of civilians for hard labour, often in brutal conditions that resulted in the deaths of hundreds of thousands.
Collapse of the sphere
By 1943, Japan’s military expansion had stalled, and its defensive lines across the Pacific began to collapse under the weight of Allied advances.
American forces pushed back island by island, while British and Commonwealth troops launched new attacks in Burma and Malaya.
As Japanese defeats multiplied, local support for the Co-Prosperity Sphere gradually weakened.
Nationalist leaders who had once cooperated with Tokyo turned against the occupation, especially after promises of real independence remained unfulfilled.
In early 1945, the Burma National Army that had previously cooperated with Japan under promises of independence defected to the Allies under Aung San's leadership in March 1945, which helped them drive Japanese forces out of the country.
In the Philippines, American landings triggered widespread uprisings, and guerrilla units dismantled Japanese communication lines.
On the Japanese home front, factory production collapsed under heavy bombing, and shipping routes came under constant attack.
Japan's failed Operation U-Go in 1944 attempted to invade British India by an advance into Manipur and by the battles of Imphal and Kohima, and it further weakened its position in Burma.
After the Soviet invasion of Manchuria and the atomic bombings of Hiroshima and Nagasaki had taken place, Japan surrendered in August 1945, and this surrender brought the Co-Prosperity Sphere to a sudden end.