Japan Occupies Indochinese Ports Summary

  • Last updated on November 10, 2022

The Japanese Imperial Army, in the midst of an invasion of China, determined that an occupation of French Indochina was critical to the success of that endeavor as well as to its plans for Japanese military expansion into Southeast Asia generally. The Japanese government convinced the Vichy French government to allow it to occupy Indochina, thereby solidifying its hold on the region.

Summary of Event

The Japanese military establishment seized control of its country’s government during the 1930’s. Through the use of both assassination and intimidation, the Imperial Japanese Army, claiming that its policies reflected the will of Emperor Hirohito, established itself as the main political force in the island nation. The army planned to strengthen its hold on power by expanding the empire through the conquest of neighboring countries and exploiting their resources. The concept of empire, however, was not new to Japan. Just before the turn of the twentieth century, the military had seized control of Korea, described as “a dagger pointed at the heart of the empire.” In late 1931 and early 1932, the army overran Manchuria, established a puppet emperor, Puyi, and began a major exploitation of the newly conquered territory’s natural resources. [kw]Japan Occupies Indochinese Ports (Sept., 1940) [kw]Indochinese Ports, Japan Occupies (Sept., 1940) [kw]Ports, Japan Occupies Indochinese (Sept., 1940) French Indochina;Japanese occupation of ports Japan;occupation of French Indochina ports [g]Cambodia;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]East Asia;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]Indochina;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]Japan;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]Laos;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]Southeast Asia;Sept., 1940: Japan Occupies Indochinese Ports[10290] [g]Vietnam;Sept., 1940: Japan Occupies Indochinese Ports[10290] [c]Colonialism and occupation;Sept., 1940: Japan Occupies Indochinese Ports[10290] [c]Diplomacy and international relations;Sept., 1940: Japan Occupies Indochinese Ports[10290] [c]World War II;Sept., 1940: Japan Occupies Indochinese Ports[10290] [c]Wars, uprisings, and civil unrest;Sept., 1940: Japan Occupies Indochinese Ports[10290] Matsuoka, Yōsuke Tojo, Hideki Arita, Hachirō

The Japanese army invaded China proper in July of 1937. The army was committed to conquering China, and it engaged in a tremendous expenditure of men and equipment. Despite a series of impressive victories against the opposition Chinese Nationalist and Communist forces in the field, however, the Japanese high command never succeeded in gaining complete control of China’s vast territory. In 1940, the Japanese high command considered the occupation of French Indochina’s ports critical to the success of its long-range plans for the military, political, and economic domination of Southeast Asia. In order to proceed with the planned invasions of Malaya and the Dutch East Indies, as well as to cut off supplies to Chiang Kai-shek’s Chinese forces from the French colony’s key cities of Haiphong and Hanoi, French Indochina had to be neutralized.

In 1887, the French, after interfering in the local politics of the area for decades, had seized control of what were then the territories of Cochinchina, Annam, Tonkin, Cambodia, and Laos, and named the new political entity the Indochinese Union. For the next five decades, they exploited the area, establishing mines and rubber and rice plantations. As was common for European colonial regimes, the French authorities organized (or compelled) cheap local labor to run these operations. Their trade was forced to stop by the advent of World War II.

Yōsuke Matsuoka, Japan’s foreign minister, began negotiations with France’s Vichy government to cooperate with Japan with reference to the Indochina question. Japan had joined Germany and Italy in the Tripartite Pact Tripartite Pact (1940) of September 27, 1940. Certainly, this new ally of the victorious Germans influenced the thinking of the recently defeated French. Japanese General Issaku Nishihara arrived in Hanoi to negotiate with the French leader, Admiral Jean Decoux.

After some procrastination on its part, Vichy agreed to allow the Japanese army to occupy southern Indochina. The Japanese needed at least twelve weeks of full access to the country in order to build the additional bases necessary to launch their impending planned attacks on surrounding military targets such as the Dutch East Indies. The Japanese also succeeded in preventing Chiang Kai-shek’s Nationalist forces from receiving any more supplies through northern Indochina. The Japanese, citing their policy of “Asia for the Asians,” sought to gain support from the local population for their occupation of the country once they gained control.

The U.S. government regarded the Japanese action as tantamount to an invasion and demanded that the Japanese army withdraw from the French colony, as well as from China itself. Despite the restrictions that the United States imposed on exports to Japan, however, the island nation’s military hierarchy had no intention of giving up its recent conquests. On December 7, 1941, Japan launched an all-out attack on Allied bases in Hawaii, the Philippines, Singapore, Malaysia, and the Dutch East Indies.

The bases that the Japanese army and navy acquired in the Indochina agreement with Vichy France served as critical launching pads for the invasion of the Dutch colonial possessions to the south. The quick surrender of Singapore allowed the army to advance their timetable for the invasion of the Dutch East Indies, which quickly fell to a determined combined Japanese army and navy campaign. Once the Japanese military succeeded in conquering French Indochina, the Dutch East Indies, Malaysia, Singapore, and the Philippines, the Japanese government launched what proved to be a largely propagandistic campaign designed to regulate the politics and the economies of those countries. Called the Greater East Asia Coprosperity Sphere, Greater East Asia Coprosperity Sphere the plan called for the eventual independence of all of its participants, as well as the integration of their economies into a master plan headed by Japan itself. The Japanese called for an end to colonialism in the area, repeating the slogan of “Asia for the Asians.”

In practice, the central Japanese government left the implementation of the program to the military governments of each conquered country. As was the case in Indochina, the military simply confiscated any goods they thought of value and shipped them to the Japanese home islands, leaving the local populations in desperate economic shape. It was only after the U.S. Navy successfully interdicted Japan’s supply lines from Burma, the Dutch East Indies, and Indochina to its home islands that these critical raw materials were lost to the Japanese war effort.


Although the Japanese military profited initially from the acquisition of French Indochina, its long-term goal of incorporating the former French colonial possession into its master economic plan failed miserably. Not only did the United States and its allies defeat the Japanese in the field, but also the behavior of the Japanese occupiers toward the indigenous peoples in the lands that they conquered turned out to be so brutal and rapacious that they received little if any support when World War II began to turn against them. While it was true that the colonial peoples of Burma, India, Malaysia, the Philippines, and the Dutch East Indies sought independence, they quickly realized that with the Japanese they had only exchanged one colonial master for another. In most of the former European and American colonies, the local population aided their former masters to overthrow the Japanese occupiers.

All these nations would achieve their independence shortly after the conclusion of World War II in one manner or another. French Indochina was split up into three independent countries—Vietnam, Cambodia, and Laos. Meanwhile, Hideki Tojo, Japan’s prime minister, and Yosuke Matsuoke, its foreign minister—both of whom had played prominent roles in the adoption of the country’s plans of aggression—were charged as major war criminals by the Allied Forces at the conclusion of the war. Foreign Minister Matsuoke died June 26, 1946, before he could be tried. Prime Minister Tojo, however, was found guilty of seven major counts, sentenced to death, and executed. French Indochina;Japanese occupation of ports Japan;occupation of French Indochina ports

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Harries, Meirion, and Susie Harries. Soldiers of the Sun: The Rise and Fall of the Imperial Japanese Army. New York: Random House, 1991. A detailed description of the operations of the Japanese army and its development, from its beginnings in 1890 until its dissolution in 1945.
  • citation-type="booksimple"

    xlink:type="simple">Hoyt, Edwin P. Japan’s War: The Great Pacific Conflict. New York: Cooper Square Press, 2001. Hoyt used the 101-volume offical Japanese-language history of World War II, never previously thoroughly examined by a Western scholar. He has made excellent use of these documents to give some insight to Japanese thinking about the war.
  • citation-type="booksimple"

    xlink:type="simple">Ienaga, Saburo. The Pacific War, 1931-1945: A Critical Perspective of Japan’s Role in World War II. New York: Pantheon Books, 1978. Prominent Japanese historian and university professor questions what the Japanese people could have done to avoid their nation’s participation in World War II.
  • citation-type="booksimple"

    xlink:type="simple">Toland, John. The Rising Sun: The Decline and Fall of the Japanese Empire, 1936-1945. New York: Random House, 1970. This is the work of an American historian, but his work was ably assisted by his Japanese wife and her family, which greatly facilitated his face-to-face interviews of Japanese who had held key positions during the war. His family connections also aided him in his extensive review of the records of the Japanese Ministry of Foreign Affairs and the Military History Archives of the Japan Defense Agency.

Chinese Civil War

Stimson Doctrine

Japan Renounces Disarmament Treaties

China Declares War on Japan

Rape of Nanjing

Japan Announces the Greater East Asia Coprosperity Sphere

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