Invasion of French Indochina

The , also known as the Vietnam Expedition, was an attempt by the Empire of Japan, during the Second Sino-Japanese War to blockade China and prevent it from importing arms, fuel and 10,000 tons/month materials supplied by the United States through the Haiphong-Yunnan Fou railway line. Control of -controlled French Indochina would make the blockade of China more effective and made continuation of the drawn out Battle of South Guangxi province unnecessary.

Background

While the Japanese operation to seize Longzhou was going on in , France had signed an armistice with Germany on 22 June 1940, leading to the establishment of the Vichy government in the unoccupied part of France. Vichy France also controlled most of French overseas possessions, including Indochina, one of the last access points for China to the outside world. With the capture of Lanzhow the highway was now closed but a rail line still permitted shipment of material from Haiphong to Yunnan. Despite bombing by the Japanese the Yunnan railway remained open.

Japan began pressuring the Vichy government to close the railway and on September 5th, the South China Front Army organised the amphibious Indochina Expeditionary Army under its command to be the Japanese garrison in Indochina. Led by Major-General Takuma Nishimura, it was supported by a flotilla of ships, and planes from aircraft carriers and air bases on Hainan Island.

On September 22, Japan and Vichy Indochina signed an accord which granted basing and transit rights, but limited to 6000 the number of Japanese troops which could be stationed in Indochina, and set an overall cap of 25,000 on the total number of troops that could be in the colony at any given time. In addition, the final article of the agreement barred all Japanese land, air, and naval forces from Indochinese territory except as authorised in the accord.
*Order of Battle for Indochina Expedition

Fighting breaks out

Within a few hours columns from the under Lieutenant-General Aketo Nakamura moved over the border at three places and closed in on the railhead at Lang Son. This contravened the new agreement and ensued with a brigade of French Indochinese Colonial troops and that lasted until September 25 when Lang Son was captured. This opened the way to Hanoi. Still Vichy had defenders in the north, south, and fresh battalions barring the route from Lang Son to Hanoi were in position.

On September 23, Vichy France had approached the government in Tokyo to protest breach of the agreements by the South China Front Army forces.

Meanwhile Japanese aircraft, from the Japanese task force offshore from Haiphong in the Gulf of Tonkin, began sorties on the morning of September 24. A Vichy envoy came to negotiate, but in the meantime shore defences remained under orders to open fire against any attempt to force a landing.

On September 26, Japanese forces came ashore at Dong Tac, south of Haiphong, and began moving on the port. A second landing put tanks ashore and Haiphong was bombed, causing some casualties. By early afternoon the Japanese force of some 4,500 troops and a dozen tanks was outside Haiphong.

By the evening of September 26 fighting had died down. Japan took possession of the airfield at outside Hanoi, rail marshalling yard on the Yunnan border at Lao Cai, and athwart the railway from Hanoi to Lang Son near the border of Guangxi province, and stationed 900 troops in the port of Haiphong and a further 600 in Hanoi. These positions effectively completed the blockade of China except through the route from Burma.

On September 27, Japan signed a military alliance with Germany and Italy.

= Media links

, French newsreels archives , January 15, 1941