Japan occupies southern Indochina

On 28 July 1941 the first units of Lieutenant General Shōjirō Iida’s Japanese 25th Army went ashore in the southern part of French Indochina. No one fired at them. A week earlier the government of Vichy France, faced with a Japanese ultimatum, had agreed to the “joint defence” of the colony, and the Governor-General, Admiral Jean Decoux, had been instructed to prevent any clashes. Over the next few days the Japanese occupied the ports and airfields of Cochinchina and southern Cambodia, from which Malaya, Singapore, the Dutch East Indies and the Philippines were now within easy reach. The French administration, police and army carried on functioning, but from that moment the whole colony, from the Chinese border to the Mekong Delta, became a Japanese base area. This step, planned in Tokyo as a peaceful, risk-free “entry”, provoked a reaction that Japan’s leaders had not expected and brought war in the Pacific closer than any earlier move.

Popular chronologies state that the Japanese occupied southern Indochina, allowed the Vichy French administration to go on ruling Vietnam while “French repression continued”, and that Vichy agreed to Japanese bases. That is what happened, although the order of events was the reverse: first, on 21 and 23 July, Vichy accepted the Japanese demands; then, from 28 July, Japanese troops entered the colony; and on 29 July a formal protocol on joint defence was signed at Vichy.

The decision in Tokyo

Japan had had troops in Indochina since September 1940, when, after brief fighting at Lạng Sơn, its forces entered Tonkin, the northern part of the colony. In the spring of 1941, acting as “mediator” in the Franco-Thai War, it imposed the Treaty of Tokyo, and in May it forced economic agreements on Indochina that secured it rice, rubber and ores. The military wanted more: air and naval bases in the south, from which the British and Dutch colonies could be threatened. When talks with the Dutch on oil supplies from the Dutch East Indies broke down in June, the army and navy general staffs agreed that the right to station troops in southern Indochina had to be obtained, by force if necessary. On 25 June a liaison conference of the government and Imperial General Headquarters adopted this plan, and Emperor Hirohito approved it.

After the German attack on the USSR the Foreign Minister, Yōsuke Matsuoka, demanded that the move south be postponed and that Japan strike at Siberia instead, but he lost the argument. The Imperial Conference of 2 July 1941 decided to carry out the plan regarding Indochina and Thailand and to prepare for a further advance south, “not shrinking” from war with Britain and the United States. The Americans, who were reading the encrypted traffic of the Japanese Foreign Ministry, followed these preparations almost as they happened. When Matsuoka continued to obstruct government policy, the Prime Minister, Prince Fumimaro Konoe, tendered the resignation of the entire cabinet on 16 July and on 18 July formed a new one without him. Admiral Teijirō Toyoda became Foreign Minister. The change of cabinet altered nothing as regards Indochina, as Tokyo immediately assured Vichy and Berlin.

An ultimatum for Vichy

The negotiations were conducted at Vichy. On 14 July the Japanese ambassador, Sotomatsu Katō, presented to the Deputy Prime Minister, François Darlan, the effective head of Marshal Philippe Pétain’s government, the demands that Tokyo had sent him two days earlier. Japan wanted the right to bring into southern Indochina the “necessary number” of troops, warships and air units; eight airfields, including those at Saigon, Biên Hòa, Nha Trang, Phnom Penh and Siem Reap; naval bases at Saigon and in Cam Ranh Bay; freedom of movement for its troops; and the right to issue money for them. The details were to be settled on the spot by the military – on the Japanese side by Major General Raishirō Sumita, head of the military mission in Hanoi – but if they failed to finish before the troops arrived, the landing was to go ahead regardless. Matsuoka, while still minister, justified the demands by the British and American “encirclement” of Japan and warned that Indochina faced the fate of Syria, where the Vichy forces had just capitulated: France, unable to afford to defend its colonies, could keep them only by placing “absolute trust” in Japan.

Vichy had nothing to defend itself with. Indochina was held by a few tens of thousands of soldiers, most of them locally recruited, with obsolete weapons and no hope of reinforcements from France, with which sea communications had been practically severed since 1940. The government tried to sound out the Germans, but Berlin, preoccupied with the war in the east, had no intention of defending French colonies against its own ally, and Tokyo itself had asked Germany and Italy to advise France to give way. On 19 July Katō demanded a reply by 6 p.m. on 22 July and warned that the troops would move whatever it was. The Council of Ministers decided to yield. On 21 July Darlan handed Katō France’s consent and explained that France had no other choice. He admitted that there would be no shortage of people to point out the paradox: France had defended Syria against the British yet was letting the Japanese into Indochina. He asked only that Japan give a public assurance that French sovereignty would be respected, that French troops would not be removed from their garrisons and that their installations would not be occupied.

The French wanted the document to state that the presence of Japanese troops was “temporary” and did not amount to a military occupation, and that the Indochinese army would take part in no offensive operations. Tokyo refused to set any time limit and forbade its ambassador to use the word “temporary”: Japanese troops were to remain “until the danger has disappeared”. On 23 July the two sides concluded an agreement on the joint defence of Indochina, the details of which were to be set out in a protocol, and at noon on 26 July the Japanese government announced that Japan and France had decided to defend the colony jointly. On 28 July the Japanese Privy Council approved the protocol, and on 29 July Darlan and Katō signed it at Vichy. In it Japan undertook to respect the territorial integrity of Indochina and French sovereignty, while France agreed to the stationing of Japanese troops throughout the colony and to their use of its airfields and ports. Reporting to Tokyo, Ambassador Katō had no illusions about the substance of the agreement: the French had given way because they saw Japan’s determination and speed of action, and Japan was carrying out a military occupation under the guise of a mutual agreement.

A peaceful entry

The troops were ready before Vichy replied. As early as 5 July the 25th Army had been formed in Tokyo for the occupation of southern Indochina. Its core consisted of units transferred from southern China and from Hainan, including the Imperial Guards Division. The transport convoys assembled in the port of Sanya in the south of the island, covered by the ships of Vice-Admiral Masaichi Niimi’s 2nd China Expeditionary Fleet, led by the heavy cruiser Ashigara. The navy called the whole undertaking Operation Fu. The date of entry was postponed several times: at first 17 July was mentioned, then 20 and 24 July, and in the end the troops sailed once the agreement with Vichy was a foregone conclusion.

On 28 July the first units began landing on the coast of southern Indochina. Over the following days the Japanese occupied Saigon and its port; Cam Ranh Bay, one of the finest natural harbours in South-East Asia; and the airfields at Biên Hòa, Nha Trang, Sóc Trăng and in Cambodia. Accounts differ on the order of individual places and dates, but they agree that the entry took place without fighting and was complete by early August. The headquarters of the 25th Army was set up in Saigon. On 31 July the Japanese navy created a separate Southern Expeditionary Fleet for the new bases, whose commander, Vice-Admiral Noboru Hirata, took over responsibility for Indochinese waters from Niimi on 11 August. According to French studies, some 50,000 Japanese troops were from then on stationed in Indochina as a whole.

Under the agreement the French garrisons stayed where they were, and the French flag continued to fly over government buildings. In practice the division of tasks was clear: the French were responsible for order and for the defence of the north of the colony, the Japanese for the south, where their air force and navy could use the bases freely. Indochina also bore the costs of the Japanese presence. According to Japanese calculations, between October 1940 and March 1945 the colonial administration paid out more than 723 million piastres for the upkeep of Japanese troops, a sum comparable to the current expenditure of the colonial administration itself, which meant that the Japanese did not need to issue occupation currency in Indochina.

Two yokes

Decoux, who throughout behaved as a loyal executor of the Marshal’s orders, regarded the agreement as the only way of preserving French rule. Japan, in order not to burden itself with administering a foreign country or to provoke a “race war”, allowed the French administration to go on governing, on condition of its loyalty. For the people of Vietnam, Cambodia and Laos this meant a double oppression. The Vietnamese spoke of “one neck under two yokes”. The colony had to supply Japan with rice, maize, rubber and ores, increasingly at the expense of its own inhabitants.

French rule, though dependent on Japan, did not soften its course towards its subjects. Repression did indeed continue. The communist-led uprisings of the autumn of 1940 in Tonkin and Cochinchina had been crushed with great severity, with executions, mass arrests and the bombing of villages, and military courts were still trying their participants in 1941. At the same time Decoux persecuted the supporters of Charles de Gaulle, and Vichy’s laws against Jews and Freemasons were in force in the colony. The Japanese did not interfere, while maintaining contacts with Vietnamese nationalists – except the communists – and with the religious movements of Caodaism and Hòa Hảo. In May 1941 the communists gathered around Hồ Chí Minh founded in the mountains near the Chinese border the League for the Independence of Vietnam, the Việt Minh, which was to fight both the French and the Japanese.

A response no one foresaw

Tokyo calculated that since France had agreed and no shots had been fired, the United States and Britain would confine themselves to protests. This was the forecast the General Staff presented to the government, and Konoe later claimed that the army and navy had assessed the situation in the same way. Only a few, Matsuoka among them, warned of war. Washington, which knew Japan’s demands on Vichy from decrypted telegrams, reacted faster and more sharply. On 23 July the Acting Secretary of State, Sumner Welles, told Ambassador Kichisaburō Nomura that the United States had to regard this step as the last one before a policy of expansion and conquest in the region of the South Seas, and that Secretary of State Cordell Hull saw no basis for continuing the talks. On 24 July President Franklin Delano Roosevelt proposed to Nomura the neutralisation of Indochina under a guarantee by the United States, Britain, the Netherlands, China and Japan, with Japan assured of free access to the colony’s rice and raw materials. Tokyo did not accept the proposal.

On 26 July, two days before the first landings, Roosevelt froze Japanese assets in the United States. Britain denounced its trade agreements with Japan and likewise froze its assets, and the Dutch East Indies also froze Japanese assets and soon afterwards repudiated the oil supply agreement. Tokyo responded on 28 July, the day of the first landings, with its own restrictions on foreign capital in Japan. As late as 26 July the Japanese General Staff recorded in its war diary that it did not expect a total oil embargo. In the margin of this entry someone later added that this had been a mistaken assessment, and not only on the part of its authors but of the entire General Staff and the War Ministry. From 1 August American export licences in practice cut Japan off from oil, whose stocks, by the navy’s reckoning, would last about a year and a half.

Place in the war

The entry into southern Indochina was the moment at which Japanese expansion in Asia ceased, in Washington’s eyes, to be a Chinese matter and became a threat to British, Dutch and American possessions. The oil embargo faced Tokyo with a choice between withdrawing from Indochina and China and going to war for the oil of the Dutch East Indies. The navy, which without American fuel was losing strength month by month, began to press for a quick decision. On 6 September an Imperial Conference decided to prepare for war with the United States, Britain and the Netherlands if negotiations produced no result by the beginning of October. In October Konoe resigned and General Hideki Tōjō became Prime Minister. In November Tokyo was still offering, in return for an easing of the embargo, to move its troops from southern to northern Indochina, while the American note of 26 November demanded the withdrawal of all Japanese forces from China and from the whole of Indochina.

The bases seized in July 1941 served exactly the purpose the Americans and British had feared. On 8 December 1941 troops set out from Indochina through Cambodia and entered Thailand, and convoys carrying the landing forces for Malaya sailed from the ports of Indochina and Hainan. On 10 December naval aircraft from the airfields around Saigon sank the British capital ships Prince of Wales and Repulse off the coast of Malaya. At the same time Japan struck at Pearl Harbor, the Philippines and Hong Kong.

The French administration in Indochina survived for more than three years. When France had been liberated and the Americans were approaching the coasts of Asia, the Japanese came to see it as a threat, and on 9 March 1945 they overthrew it by force, interning Decoux and the French troops. Japanese rice requisitions, double exploitation and Allied bombing contributed to the famine in northern Vietnam in 1944–1945. After Japan’s surrender the Việt Minh took power, and the attempt to restore French rule led in 1946 to the Indochina War. The road to it began in July 1941, when Vichy, in order to keep the colony, placed it in the care of the Japanese army.