Japanese invasion of French Indochina
The Japanese invasion of French Indochina (仏印進駐, Futsu-in shinchū) was a short undeclared military confrontation between Japan and Vichy France in northern French Indochina. Fighting lasted from 22 to 26 September 1940; the same time as the Battle of South Guangxi in the Sino-Japanese War, which was the main objective as to why Japan occupied Vietnam during this time.
The main objective of the Japanese was to prevent China from importing arms and fuel through French Indochina along the Kunming–Haiphong railway, from the Indochinese port of Haiphong, through the capital of Hanoi to the Chinese city of Kunming in Yunnan.[1]
Although an agreement had been reached between the French and Japanese governments prior to the outbreak of fighting,[2] authorities were unable to control events on the ground for several days before the troops stood down. As per the prior agreement, Japan was allowed to occupy Tonkin in northern Indochina, and thus effectively blockade China.
Franco-Japanese negotiations[edit]
On 19 June, Japan took advantage of the defeat of France and the impending armistice to present the Governor-General of Indochina, Georges Catroux, with a request, in fact an ultimatum, demanding the closure of all supply routes to China and the admission of a 40-man Japanese inspection team under General Issaku Nishihara. The Americans became aware of the true nature of the Japanese "request" through intelligence intercepts since the Japanese had informed their German allies. Catroux initially responded by warning the Japanese that their unspecified "other measures" would be a breach of sovereignty. He was reluctant to acquiesce to the Japanese, but with his intelligence reporting that Japanese army and navy units were moving into threatening positions, the French government was not prepared for a protracted defense of the colony.[3] Therefore, Catroux complied with the Japanese ultimatum on 20 June.[4] Before the end of June the last train carrying munitions crossed the border bound for Kunming.[3] Following this humiliation, Catroux was immediately replaced as governor-general by Admiral Jean Decoux. He did not return to France, however, but to London.[4][5]
On 22 June, while Catroux was still in his post, the Japanese issued a second demand: naval basing rights at Guangzhouwan and the total closure of the Chinese border by 7 July. Issaku Nishihara, who was to lead the "inspection team", the true purpose of which was unknown, even to the Japanese, arrived in Hanoi on 29 June. On 3 July, he issued a third demand: air bases and the right to transit combat troops through Indochina. These new demands were referred to the government in France.[3][6]
The incoming governor, Decoux, who arrived in Indochina in July, urged the government to reject the demands. Although he believed that Indochina could not defend itself against a Japanese invasion, Decoux believed it was strong enough to dissuade Japan from invading. At Vichy, General Jules-Antoine Bührer, chief of the Colonial General Staff, counselled resistance. The still neutral United States had already been contracted to provide aircraft, and there were 4,000 Tirailleurs sénégalais in Djibouti that could be shipped to Indochina in case of need.[6] In Indochina, Decoux had under his command 32,000 regulars, plus 17,000 auxiliaries, although they were all ill-equipped.[4]
On 30 August 1940, the Japanese foreign minister, Yōsuke Matsuoka, approved a draft proposal submitted by his French colleague, Paul Baudouin,[a] whereby Japanese forces could be stationed in and transit through Indochina only for the duration of the Sino-Japanese War. Both governments then "instructed their military representatives in Indochina to work out the details [although] they would have been better advised to stick to Tokyo–Vichy channels a bit longer". Negotiations between the supreme commander of Indochinese troops, Maurice Martin, and General Nishihara began at Hanoi on 3 September.[7]
During negotiations, the government in France asked the German government to intervene to moderate its ally's demands. The Germans did nothing. Decoux and Martin, acting on their own, looked for help from the American and British consuls in Hanoi, and even consulted with the Chinese government on joint defence against a Japanese attack on Indochina.[7]
On 6 September, an infantry battalion of the Japanese Twenty-Second Army based in Nanning violated the Indochinese border near the French fort at Đồng Đăng. The Twenty-Second Army was a part of the Japanese Southern China Area Army, whose officers, remembering the Mukden incident of 1931, were trying to force their superiors to adopt a more aggressive policy. Following the Đồng Đăng incident, Decoux cut off negotiations. On 18 September, Nishihara sent him an ultimatum, warning that Japanese troops would enter Indochina regardless of any French agreement at 22:00 (local time) on 22 September. This prompted Decoux to demand a reduction in the number of Japanese troops that would be stationed in Indochina. The Japanese Army General Staff, with the support of the Japanese Southern China Area Army, was demanding 25,000 troops in Indochina. Nishihara, with the support of the Imperial General Headquarters, got that number reduced to 6,000 on 21 September.[8]
Seven and a half hours before the expiration of the Japanese ultimatum on 22 September, Martin and Nishihara signed an agreement authorizing the stationing of 6,000 Japanese troops in Tonkin north of the Red River, the use of four airfields in Tonkin, the right to move up to 25,000 troops through Tonkin to Yunnan and the right to move one division of the Twenty-Second Army through Tonkin via Haiphong for use elsewhere in China. Already on 5 September, the Japanese Southern Army had organized the amphibious Indochina Expeditionary Army under Major-General Takuma Nishimura, it was supported by a flotilla of ships and aircraft, both carrier- and land-based. When the accord was signed, a convoy was waiting off Hainan Island to bring the expeditionary force to Tonkin.[9]
Invasion[edit]
The accord had been communicated to all relevant commands by 21:00, an hour before the ultimatum was set to expire. It was understood between Martin and Nishimura that the first troops would arrive by ship. The Twenty-Second Army, however, did not intend to wait to take advantage of the accord. Lieutenant-General Aketo Nakamura, commander of the 5th (Infantry) Division, sent columns across the border near Đồng Đăng at precisely 22:00.[9]
At Đồng Đăng there was an exchange of fire that quickly spread to other border posts overnight. The French position at the railhead at Lạng Sơn during the Battle of Lạng Sơn was surrounded by Japanese armour and forced to surrender on 25 September. Before surrendering, the French commanders had ordered the breechblocks of the 155mm cannons thrown into a river to prevent the Japanese from using them. During the Sino-French War of 1884–1885, the French had been forced into an embarrassing retreat from Lạng Sơn in which equipment had likewise been thrown into the same river to prevent capture. When the breechblocks of 1940 were eventually retrieved, several chests of money lost in 1885 were found also.[9] Among the units taken captive at Lạng Sơn was the 2nd Battalion of the 5th Foreign Infantry Regiment that contained 179 German and Austrian volunteers, whom the Japanese in vain tried to induce to change sides.[10]
On 23 September, the French Government protested the breach of the agreements by the IJA to the Japanese government.
On the morning of 24 September, Japanese aircraft from aircraft carriers in the Gulf of Tonkin attacked French positions on the coast. A French Government envoy came to negotiate; in the meantime, shore defenses remained under orders to open fire on any attempted landing.
On 26 September, Japanese forces came ashore at Dong Tac, south of Haiphong, and moved on the port. A second landing put tanks ashore, and Japanese planes bombed Haiphong, causing some casualties. By early afternoon the Japanese force of some 4,500 troops and a dozen tanks were outside Haiphong.
By the evening of 26 September, fighting had died down. Japan took possession of Gia Lam Airbase outside Hanoi, the rail marshaling yard on the Yunnan border at Lao Cai, and Phu Lang Thuong on the railway from Hanoi to Lạng Sơn, and stationed 900 troops in the port of Haiphong and 600 more in Hanoi.