Japanese invasion of French Indochina

The occupation of Indochina also fit into Japan's long-term plans. Japanese leaders then dreamed of creating what they called a Greater East Asia Co-Prosperity Sphere, an economic and political coalition of Asian nations tied to Japan. Together, these Asian countries would expel Western imperialists and capitalists then share trade, resources and commodities between themselves. In early 1940, troops of the Imperial Japanese Army (IJA) moved to seize southern Guangxi and Longzhou County, where the eastern branch of the Kunming–Hai Phong Railway reached the border at the Friendship Pass in Pingxiang. They also tried to move west to cut the rail line to Kunming. The railway from Indochina was the Chinese government's last secure overland link to the outside world. On 10 May 1940, Germany invaded France. On 22 June, France signed an armistice with Germany (in effect from 25 June). On 10 July, the French parliament voted full powers to Marshal Philippe Pétain, effectively abrogating the Third Republic. Although much of metropolitan France came under German occupation, the French colonies remained under the direction of Pétain's government at Vichy. Resistance to Pétain and the armistice began even before it was signed, with Charles de Gaulle's appeal of 18 June. As a result, a de facto government-in-exile in opposition to Pétain, called Free France, was formed in London. ==Franco-Japanese negotiations==

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. Therefore, Catroux complied with the Japanese ultimatum on 20 June. Before the end of June the last train carrying munitions crossed the border bound for Kunming. 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. 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. 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. 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. ==Invasion==

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. 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. ==Aftermath==

The Japanese tendered an official apology for the incident at Lạng Sơn on 5 October 1940. The Japanese-occupied towns were returned to French control and all French prisoners were released. In May 1971, a document from senior North Vietnamese political figure Trường Chinh was published in English translation which denounced allegations that the Japanese were treated as liberators after assisting the removal of the French, even afterwards turning on the local Viet Minh resistance forces and committing atrocities. With the Allied invasion of France in 1944, Japan suspected that the French authorities in Indochina might assist Allied operations in the region. Therefore, Japan deposed the French authorities in the spring of 1945, imprisoning the French administrators and taking direct control of Indochina until the end of the war. At that point, Vietnamese nationalists under the Viet Minh banner took control in the August Revolution, and issued a Proclamation of Independence of the Democratic Republic of Vietnam. The Japanese occupation of Indochina helped strengthen the Viet Minh and contributed to the outbreak of the First Indochina War in 1946 against French rule. == Explanatory notes ==