Old map of Indochina showing Cambodia, Laos and Vietnam (then Tonkin China, Annan and Cochin China).

Japanese Occupation of Vichy French Indochina - 1940-1941

© 2012 Bob Hackett and Sander Kingsepp

111 BC:
Ancient Vietnamese tribes and land are incorporated into the Chinese Han Dynasty. For the next thousand years, Vietnam remains mostly under Chinese rule. In 938 AD, the Vietnamese defeat Southern Han forces and regain independence. Renamed Ši Viet, Vietnamese defeat invasions by the Mongols. Between the 11th and 18th centuries, Vietnam expands southward conquering the kingdom of Champa and part of the Khmer Empire.

January 1860:
Cambodia. French naturalist and explorer Henri Mouhot “discovers” Angkor Wat, the largest Hindu temple complex in the world, built by the Khmer's King Suryavarman II (1113–1150) as state temple and capital city.

Angkor Wat, Cambodia
(Hackett Collection)

The French forcibly make Cambodia a French Protectorate to expand their colonial empire. In 1867, most of Cambodia is ceded to France, but Inner Cambodia remains a Siamese (Thai) possession. In 1887, French Indochina is formed from Vietnam and Cambodia. Most of the French settlers are concentrated in Cochinchina, the southern third of Vietnam, based around Saigon (now Ho Chi Minh City).

French troops invade Northern Laos. In 1893, the French request cession of all Laotian lands east of the Mekong River. This leads to the Franco-Siamese War and the cession of Laos to France. In 1906, the French also receive Inner Cambodia.

3 September 1939: World War II Begins:
London. Two days after the German invasion of Poland, and after the United Kingdom's ultimation to withdraw is rejected, at 1115, Prime Minister Neville Chamberlain declares war on Germany

10 June 1940: Italy
Rome, Italy. Italian fascist dictator Benito Mussolini declares war on Great Britain and France.

21 June 1940: Franco-German Armistice:
Compiegne Forest, France. France surrenders to Germany, in a ceremony designed by Adolf Hitler to humiliate the defeated French, in the same historic railway coach and exact spot where, on 11 Nov '18, the Armistice ending World War I was signed. Later, the coach is removed to Berlin.

22 June 1940:
The new French state, known as Vichy France, collaborates with the Nazis and fascist Italians. Eighty-four year-old General and Marshal of France Henri Philippe Petain ("The Hero of Verdun") becomes head of state. Indochina's colonial administration is isolated and cut off from outside supplies.

24 June 1940: Franco-Italian Armistice:
Villa Inchesa, near Rome. At 1815, the French surrender to Mussolini. The Franco-Italian Armistice is effective at 1235, 25 Jun '40, simultaneously with the Franco-German Armistice.

1 August 1940:
Japan. In a press interview, Minister for Foreign Affairs, Matsuoka Yosuke formally announces the concept of a "Greater East Asia Co-Prosperity Sphere.” The idea had earlier originated with Imperial Army General Arita Hachiro Arita who also had served as Minister for Foreign Affairs.

5 September 1940:
The IJA South China Army organizes an amphibious Indochina Expeditionary Army to move into Indochina supported by ships and planes from carrier and air bases on Hainan Island.

15 September 1940:
Carrier SORYU's air group is transferred to sister HIRYU.

Carriers HIRYU and SORYU by T. Yuki

16 September 1940:
Thw winds of war reach America's shores. President Franklin D. Roosevelt signs the "The Selective Training and Service Act of 1940" a.k.a. "The Draft" into law under which 16 million American men eventually register for military duty.

17 September 1940:
Off Hainan, China. HIRYU and SORYU's air group are active supporting the ocupation of northern Indochina through early October.

ca. 19 September 1940:
Hanoi. IJA MajGen Nishihara Issaku Nishihara, head of the Japanese mission in Indochina demands, on threat of immediate invasion, the new Vichy-appointed Governor General, Admiral Jean Decoux, grant Japan permission to use Indochina's chief port, Haiphong, as a naval and air base and use of the French-owned Indochinese Railway to transport Japanese equipment and troops for an attack on South China.

Chungking. Generalissimo Chiang Kai-shek, aware that the invasion of Yünnan Province through Indochina would cut off his supplies, announces that Chinese troops will counter-invade if Japanese forces are permitted to enter French Indochina.

Faced with the prospect of double invasion, Admiral Decoux pleads for time to communicate with Vichy. The Colonial Government cancels military leaves, closes the port of Haiphong, suspends railway traffic throughout the colony, mans coastal defenses, barricades streets in Haiphong and prepares to evacuate women and children from coastal towns. A Japanese fleet steams outside Haiphong and Japanese troops on the occupied Hainan prepare for active duty.

London. British Ambassador Sir Robert Craigie advises the Japanese Foreign Office of the British Government's interest in preserving the status quo of Indochina.

Shanghai. Admiral Thomas C. Hart, CinC, United States Asiatic Fleet, steams unexpectedly into Shanghai on the cruiser USS MARBLEHEAD (CL-12).


Hanoi. Vichy French Admiral Decoux receives General Nishihara and informs him that French Indochina is unable to accept the terms of the ultimatum and will resist any attempt at invasion. The Japanese return 24 hours later with a request that certain unspecified military facilities be granted to Japan.

22 September 1940:
Knowing it is powerless to intervene, the Vichy Government in mainland France chooses to give Indochina to Japan. In a "limited" basic agreement Vichy signs an accord directly with Tokyo that cedes airfields and allows up to 6,000 Japanese troops to be stationed in Indochina (Cambodia, Laos and Vietnam). In Hanoi, Admiral Decoux and General Nishihara agree on details of the occupation.

News of the accord brings Chinese action. Troops on the Yunnan frontier move into Indochina and are met in a sharp engagement by French colonial troops forced into fighting for Japan.

That same day, LtGen Nakamura Akihito's IJA 5th Division moves over the border at three places and closes on the railhead at Lang Son, near Longzhou. This action contravenes the Japanese Government's new agreement with Vichy. In the Battle of Lang Son, a brigade of Indochinese colonial troops and Foreign Legionaires opposes the IJA for three days. The Japanese are victorious and open the way to Hanoi.

The Roosevelt Administration responds to Japanese expansion in Indochina by citing the United States Export Control Act and places a ban on the export of steel, scrap metal and all oil exports, including aviation fuel, to Japan. The embargo hits the Imperial Japanese Navy (IJN) hard since the Navy depends on United States oil imports for 80-90 percent of its fuel. Great Britain and the Netherlands also embargo oil exports to Japan.

Tokyo. The IJN estimates that it has less than two years of bunker oil remaining. Therefore, the IJN lends its support to existing Japanese plans to seize oil resources in the Dutch East Indies.

September 1940:
Japan sends a large mission to Batavia, Java. Imports from the Dutch East Indies are about 4.5 million barrels annually, but Japan demands 22 million barrels (40 percent of Dutch annual production). This amount is almost exactly equal to Japan's previous oil imports from the United States. The Dutch negotiate until November when they finally agree to an increase of 14.5 million barrels annually.

23 September 1940:
Vichy France protests the IJA's breach of the agreements to the Japanese Government in Tokyo.

24 September 1940:
Aircraft from carrier HIRYU in the Gulf of Tonkin attack Vichy French positions on the coast. Vichy shore defenses remain under orders to open fire on any attempted landing.

25 September 1940:
S of Haiphong. Japanese forces come ashore at Dong Tac and move on the port. They make a second landing and put tanks ashore. Japanese planes bomb Haiphong. By early afternoon, a force of some 4,500 IJA troops and a dozen tanks is outside Haiphong.

26 September 1940:
The Japanese take possession of Gia Lam Airbase outside of Hanoi, the rail marshalling yard on the Yunnan border at Lao Cai and Phu Lang Thuong on the railway from Hanoi to Lang Son. They station 900 troops in the port of Haiphong and 600 others in Hanoi.

27 September 1940: - The Axis Tripartite Pact:
Berlin, Germany. The Tripartite Pact establishing the Axis Powers is signed by Foreign Minister Joachim von Ribbentrop of Germany, Ambassador Kurusu Saburo of Japan and Foreign Minister Count Galeazzo Ciano of Italy. The parties formally recognize each other's spheres of interest and undertake "to assist one another with all political, economic and military means when one of the three contracting powers is attacked…"

Ciano, Ribbentrop and Kurusu signing Tripartite Pact

October 1940:
A border dispute between Siam (now Thailand) and French Indochina erupts into armed conflict. Siam launches the French-Siam War.

21 November 1940:
Japan decides to support Thailand’s demands to regain territory from the French and supplies aircraft and arms to Bangkok.

14-16 January 1941: Operation "S" – Northern French Indochina Incursion.
Japanese troops enter French Indochina.

22 January 1941:
Heavy cruiser IJN ASHIGARA is assigned to the South French Indochina Expedition. Departs Samah, Hainan Island.

25 January 1941:
Kaibokan IJN SHIMUSHU and mineweeper IJN W-17 arrive at Haiphong harbor, N Indochina, to observe French fleet units stationed there.

28 January 1941:
Light cruiser IJN NATORI arrives at Saigon, S Indochina.

29 January 1941:
ASHIGARA arrives at Saigon.

31 January 1941:
Saigon. The Japanese sponsor a "Conference for the Cessation of Hostilities." Preliminary documents for a cease-fire between the governments of Vichy France and the Kingdom of Siam are signed aboard NATORI. The Japanese force the French to accept a peace treaty that returns parts of Cambodia and Laos, taken by the French in 1867, to Siamese control. That same day, ASHIGARA departs Saigon.


9 February 1941:
NATORI departs Saigon.

25 May 1941:
Haiphong, North French Indochina. IJA soldiers smash open the doors of two warehouses and seize $10 million worth of American products destined for China.

12 July 1941:
ASHIGARA is assigned to the Southern French Indochina Occupation Expedition.

23 July 1941:
Japanese and collaboratist French authorities arrive at an "understanding" regarding the use of air facilities and harbors in Southern Indochina.

24 July 1941:
Japanese forces occupy Indochina, including airfields in Saigon (Ho Chi Minh City) at Tan Son Nhut, Thudaumot and Bien-hoa and bases at Soc Trang, Nha Trang. Tourane (Da Nang) and Siemreap, Pnom Penh and Kompong-tom in Cambodia. IJN vessels also move into the ports of Saigon, Tourane and Camranh Bay. IJA tanks clank through Saigon's colonial streets.

25 July 1941: Operation "FU" - The occupation of Southern French Indochina:
A total of 39 IJA/IJN troopships depart Hainan Island for Saigon, escorted by aircraft from HIRYU and SORYU. That same day, ASHIGARA departs Samah.

29 July 1941:
ASHIGARA arrives at Saigon.

30 July 1941:
Under a new pact with the Vichy French for "common defense" of the territory, more Japanese enter French Indo-China. 40,000 troops move into the Saigon area alone.

11 August 1941:
ASHIGARA departs Saigon for Samah.

8 December 1941: The Beginning of the Pacific War:
From occupied air and naval bases in French Southern Indochina, the Japanese launch aircraft and naval vessels in support of their invasions of British Malaya (now Malaysia and the Republic of Singapore) and the Commonwealth of the Philippines (now Republic of the Philippines).

At 0300, an IJA Division crosses the French Indochina-Thailand border from the direction of Phnom Penh, Cambodia. Later that morning, elements of the Imperial Guards Division land near Bangkok. Both forces advance swiftly toward Bangkok, encountering little resistance. By that evening the Thai capital is occupied.

Singapore. At 1710, Royal Navy Vice Admiral Sir Tom S. V. Phillips sorties to attack the Malaya invasion transports with his "Force Z" consisting of Captain J. C. Leach's new battleship HMS PRINCE OF WALES, Captain (later Vice Admiral) W. G. Tennant's old battlecruiser HMS REPULSE, destroyers HMS ELECTRA, EXPRESS, TENEDOS and Australian destroyer HMAS VAMPIRE.

HMS PRINCE OF WALES and REPULSE at Royal Navy Base, Singapore

10 December 1941:
Saigon and Thudamot, French Indochina. The Genzan, Kanoya and Mihoro Kokutai (Naval Air Groups) of Rear Admiral (later Vice Admiral) Matsunaga Sadaichi's (former CO of ISUZU) 22nd Air Flotilla launch 94 torpedo-bombers (Type 96 Mitsubishi G3M2 "Nells" and Type 1 G4M1 "Bettys") that overwhelm Phillips "Force Z" and sink both HMS PRINCE OF WALES and REPULSE off Kuantan, Malaya.

IJN G4M1 Betty (Tamiya) and G3M2 Nell (Hasegawa) torpedo bombers over Force "Z"

-Bob Hackett and Sander Kingsepp

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