Masayuki (Seiko) Yokoyama was a career Japanese diplomat. During World War II he served as Minister for Economic Affairs of the Japanese diplomatic mission in Indochina and as Director of the Japanese Cultural Center in Saigon. After the March 1945 coup d’état — during which Japanese and Vietnamese deposed the Vichy French colonial state — he served as the primary contact to Emperor Bảo Đại and his new ‘Empire of Vietnam’ [Đế Quốc Việt Nam] government in Huế.
His memoir of events in Indochina during World War II is held at the Archives nationales d’outre mer in Aix-en-Provence, France. A PDF is available here.
Two interesting pieces of information are contained within. The first relates to the possible appointment of Ngô Đình Diệm as president of the Japanese-sponsored Empire of Vietnam. Scholars like David Marr have dismissed this event as fictional, despite Bảo Đại himself writing that he offered Diệm the post. In Vietnam 1945: The Quest for Power, Marr writes:
“… knowledgeable Japanese become evasive, often referring vaguely to Cuong De being ‘too old’ and infirm, or to Diem being sent a message in Saigon but not responding. Some Vietnamese believe Diem received an offer but declined … . Given the energetic political maneuvering of the entire Ngo family at this point in time, I don’t find that explanation any more convincing than the Japanese ones. Most likely General Tsuchihashi deliberately excluded both Cường Để and Diem …” (116).
Yokoyama’s memoir, however, makes clear that Bảo Đại indeed offered Diệm the position twice.
On the morning of April 4th, 1945 Bảo Đại called Yokoyama to the Imperial palace. According to the latter, Bảo Đại “asked me to immediately convey to M. Ngo-Dinh-Diem his intention to charge him with forming a new Government of National Unity of which Diem would be named Président du Conseil.” Why Diệm? Yokoyama recalled that Bảo Đại told him “according to the unanimous opinion of all those he consulted, Diem was the sole man capable of facing the grave situation at that moment, able to realize a grand national coalition that rallied around him all the political parties. In these conditions, His Majesty voluntarily renounced, he told me, his initial idea to take personal responsibility for govern the country himself.” (see pages 61-63)
Yokoyama was apparently convinced by Bảo Đại’s appeal. He recounts sending the Japanese military officials in Saigon to persuade Diệm to accept the presidency. But on the evening of April 12th Yokoyama learned that Diệm had turned down the offer: “he said that his life in exile and reclusion over the past several months had fatigued him enormously and that his general weakness would not permit him to take on this great task.” Bảo Đại did not accept the reply. On April 13th he renewed his request to Diệm, via Yokoyama, to take on the presidency of the Empire of Vietnam. Diệm declined again.
Yokoyama recounts how he later learned the true motive for Diệm’s refusal. In May 1945 Yokoyama traveled to Saigon and learned — how, he does not say — that Diệm felt he had given his commitment to Cường Để. He could not, now, turn his back on him at the moment that the exiled royal could finally take command of a new Vietnamese state. Moreover, Diệm “could not decently abandon the Prince [Cường Để] and serve the Emperor that he considered too francophile.” What’s more, “Diệm was persuaded that national union was unrealizable if he could not quickly obtain the return of Cochinchina [a French colony, not protectorate] and the three French cities [Saigon, Hanoi, Haiphong] to the territorial sovereignty of Annam, as well as the abolition of the Gouvernement Général [the federal French colonial administration] so as to affirm the independence of the Empire of Vietnam. But, the Japanese army seemed at the moment to be opposed to changes of this sort.”
Yokoyama relays Diệm had questioned the Japanese military officials sent to entreat him to accept Bảo Đại’s invitation. They promised to make good on Diệm’s request for territorial unity and independence. But not now. Instead they told him that the interests of Japan would remain foremost. Eventually, after he had accepted, the transfer of full sovereignty would come. And so the generals sent to convince Diệm to accept the post did just the opposite, convincing him to decline.
The most interesting revelation of Yokoyama’s memoir is the failed plan to bring the exiled Prince Cường Để back to Indochina. Bảo Đại was well aware of the exiled Prince’s popularity. He had long been in Japan, since the days of Phan Bội Châu’s ‘Eastern Study’ [Đông Du] movement in the early 1900s. He was a revered symbol to many Vietnamese nationalists. Bảo Đại was aware that his collaboration with France had compromised his legitimacy. And so he moved immediately to bring the Prince — his blood and family after all — back to Vietnam (Bảo Đại also succeeded, later, in bringing the former Emperor Thành Thái back to Vietnam, who the French deposed and sent to exile on Réunion, east of Madagascar).
Yokoyama recounted that “from the first hours of our official relations, he expressed to me his desire to facilitate [Cường Để’s] return to Huế, to offer him a welcome worthy of his position and his past.” It would also help realize the national unity that Bảo Đại hoped to achieve for the new Empire of Vietnam. Yokoyama noted that “it was also an act of friendship, of justice and confidence towards the Prince who was formerly considered his most dangerous adversary.” The problem was that the Japanese military authorities were wary of any action that could upset the “political status quo of Indochina” or “trouble the authority of Bảo Đại.” (see pages 97-99)
Japan’s military authorities would not sign-off on the Prince’s return until they were certain no conflict would ensue. When President Trần Trọng Kim visited Hanoi in mid-July 1945, he finalized an agreement with General Yuitsu Tsuchihashi to bring Cường Để back to Vietnam.
Bảo Đại was himself eager to publish a communique heralding the imminent return of the Prince. Cường Để hurried from his home in Sendai south to Tokyo’s airport. But by then it was August 1945 and the end of the war in the Pacific made his return to Vietnam impossible.
Cường Để would remain in Japan, choosing to publicly support Bảo Đại and his State of Vietnam government in opposition to Hồ Chí Minh’s Democratic Republic of Vietnam.