From Storm Clouds over the Pacific, 1931–1941, by Peter Harmsen (War in the Far East, Book 1; Casemate, 2018), Kindle pp. 244-246:
The city of Saigon was peeking into an uncertain future at the end of July 1941. The population knew that the Japanese military would arrive within just days, completing the takeover of French Indochina that had begun less than a year earlier in the north. As the Municipal Band was practicing for the welcoming ceremony in the city’s main square, Japanese advance parties quietly moved into the best hotels, preparing for the arrival of much larger numbers of soldiers. The French officials had promised a peaceful occupation and pointed out that Saigon was lucky to escape the fate of Syria, another French possession, which had just recently been invaded by British and Australian troops.
Despite the reassuring words from the officials, apprehension loomed everywhere. French and Japanese planes roared across the sky over Saigon, as if to symbolize rivalry between the two nations for mastery over the city. The government-controlled newspapers ominously warned people not to stage any protests against the city’s soon-to-be masters, confirming that anti-Japanese feelings were running high, especially among ethnic Chinese and sympathizers of the Free French under General Charles de Gaulle. There were even runs on the British Hong Kong-Shanghai Bank, the Chartered Bank of India, and several Chinese banks, and they had all been forced to introduce temporary limits on the amount of money that could be withdrawn at a time.
The Japanese came on July 30. At 6:30 am a Japanese transport painted in dark gray touched the pier of Saigon harbor. The deck was loaded with barges and motorboats, and the masses of infantrymen in khaki ascended from the hull to get a first glimpse of the tropical city through the morning mist. Fifteen minutes later, the next transport arrived, and by the end of the day a total of 14 vessels had carried 13,000 Japanese troops to Saigon. Thousands of others were onboard 30 vessels anchoring at Cap St. Jacques at the mouth of the Saigon River. Soldiers also poured out onto the pier at the naval base at Cam Ranh Bay.
Over the next few days the soldiers worked around the clock to unload weapons and supplies onto the docks. Trucks were leaving incessantly for new barracks being set up on the outskirts of Saigon. Japanese officers with long traditional swords tied to their belts moved into private homes that had been requisitioned and ordered vacated, relegating the original inhabitants to passenger ships anchored in the river. Several office buildings belonging to French and British firms were also taken over for military purposes. “The Japanese have landed, and the British threat to Indochina is ended,” a local paper wrote, suggesting that Britain might have repeated its invasion of Syria here, although this was sheer fabrication.
Rather than a defensive move forestalling a British invasion, it was an offensive step with deep strategic implications. As the New York Times explained, “it will put a total of 40,000 Japanese troops in Southern Indo-China, will station Japanese planes within easy bombing range of British Malaya and Burma, within an hour’s flight of Bangkok, Thailand, and will enable Japanese air patrols to cover the ship routes of the China Sea and complete Japanese air domination of all Indo-China. The five-year-old base of Cam Ranh Bay itself is virtually equidistant from the powerful American base of Cavite, guarding the approach of Manila Bay, and from the British bases of Hong Kong and Singapore. It is about 600 miles from the coast of the Netherlands Indies.”
In the French city of Vichy, half a world away, reports of the Japanese influx reached the weak German-tolerated government led by Marshal Philippe Pétain. The Vichy regime had acquiesced in the Japanese takeover, but only because it saw no other option. Resistance similar to that offered in Syria, where French troops had fought vigorously against the British and Australians, was out of the question. The clashes with Thai troops in recent months had demonstrated the desperate weakness of France in Asia. Still, the Vichy officials were furious and frustrated, and prone to blaming the United States for the unbridled Japanese advance in Asia.