Tokyo, Japan · September 6, 1941

On this date in 1941, in an Imperial Conference in Tokyo, Japa­nese offi­cials con­cluded that if diplo­matic mea­sures could not reverse the U.S. policy of em­bar­going the export of various stra­te­gic raw mate­rials (e.g., oil, iron ore, rubber, and scrap steel) to Japan by early Octo­ber, then the govern­ment and mili­tary would imple­ment the “South­ern Plan,” or “South­ern Advance”—attacking Brit­ish and Amer­i­can bases in the Asia Paci­fic region and securing the oil-rich Dutch East Indies (today’s Indo­nesia) for the nation. (The “Southern Advance” became Japanese national policy in July 1940 when both the powerful Army and Navy leadership settled their stra­tegic differ­ences over poten­tial areas of expan­sion. Ger­many’s inva­sion of France in May 1940 and the Soviet Union in June 1941 strengthened Japan’s flexibility when expanding to the south.)

On Novem­ber 5, 1941, in another Impe­rial Con­fer­ence, this one with Emperor Hiro­hito in atten­dance, Japa­nese officials were told by the hawk­ish Gen. Hideki Tōjō—war minis­ter, home minis­ter, and for the last 19 days prime minis­ter as well—that Japan’s 73 mil­lion people must be prepared to go to war with the West if diplo­macy with the U.S. and Euro­pean colo­nial powers failed to improve rela­tions and reverse trade restric­tions, which the Japa­nese govern­ment labeled acts of aggres­sion. (Imported oil, to give just one example of a stra­tegic com­modity now on the U.S. embargo list, made up about 80 per­cent of Japan’s domestic consump­tion, with­out which the nation’s eco­nomy, let alone its brutal expan­sion in China, would come to a halt.) The time for military action was tentatively set for December 1, 1941.

Two weeks later, on Novem­ber 18, 1941, the Japa­nese Diet (parlia­ment) approved a reso­lu­tion of hos­til­ity against the United States. Japan’s attacks on the U.S. naval base at Pearl Harbor, the Brit­ish crown colony of Hong Kong, British Malaya, the Dutch East Indies, the U.S. Philip­pines, and U.S. outposts on Wake and Guam islands on Decem­ber 7 and 8, 1941, drew the U.S. and its Euro­pean allies into an ex­hausting, bru­tal, and costly Asia Paci­fic war whose out­come in Japan’s favor, in the view of Pearl Harbor archi­tect Adm. Isoroku Yama­moto, was highly prob­lem­atic to start with. Only after the destruc­tion of the Japa­nese cities of Hiro­shima and Naga­saki—combined with the Soviet Union’s decla­ra­tion of war against Japan—pro­vided irrefut­able evi­dence of a no-win situ­a­tion for Japan were Hiro­hito and the Supreme War Council pushed over the edge to sue for peace in mid‑August 1945.

Asia Pacific on the Eve of War, 1939

Asia Pacific, 1939

Above: Political map of Japanese, European, and U.S. pos­ses­sions in the Asia Pacific region on the eve of the Pacific War, Septem­ber 1, 1939. Japanese control in China was tenuous.

Emperor Hirohito, 1926–198Gen. Hideki Tōjō, 1884–1948

Left: Emperor Hirohito (1926–1989) in dress uniform, 1935. On Novem­ber 2, 1941, Hiro­hito (post­humously referred to as Em­peror Shōwa) gave his con­sent for his coun­try to wage war against the United States. The next day the em­peror was briefed in detail on the proposed sneak attack on the U.S. Pacific Fleet at Pearl Harbor, Hawaii. Two days later, on Novem­ber 5, 1941, Hiro­hito approved the opera­tions plan for the war and con­tinued to hold meetings with the mili­tary chiefs and Army Minis­ter/Prime Minis­ter Hideki Tōjō until the end of the month. On Decem­ber 1, another con­fer­ence finally sanc­tioned the war against the United States, Great Britain, and the Netherlands.

Right: Gen. Hideki Tōjō (1884–1948) in mili­tary uni­form. On July 22, 1940, Tōjō was appointed Japa­nese Army Minis­ter. During most of the Paci­fic War, from Octo­ber 17, 1941, to July 22, 1944, he served as prime minis­ter as well. In that capa­city he was directly respon­sible for the deadly attack on Pearl Harbor. After the war Tōjō was arrested, sen­tenced to death for war crimes by the Inter­na­tional Mili­tary Tri­bunal for the Far East, and hanged on December 23, 1948.

Hirohito riding ShirayukiHirohito and Imperial Conference (Gozen Kaigi)

Left: Soldiers parading before Shōwa Emperor Hiro­hito. Prior to and during World War II, Hiro­hito was shown in photos and news­reels riding Shira­yuki (White Snow), his beau­ti­ful white stal­lion. The Califor­nia-born stock horse was part of his care­fully culti­vated war­rior image. A news agency reported that Hirohito made 344 appear­ances on Shirayuki.

Right: Wartime photograph of Hirohito, seated in middle, as presiding head of the Imperial Con­ference (Gozen Kaigi). Convened by the Japa­nese govern­ment in Hirohito’s presence, the Imperial Con­ference was an extra­consti­tutional con­ference that focused on foreign affairs of grave national impor­tance. Hirohito was also a mem­ber of the Imperial General Head­quarters-Govern­ment Liai­son Con­ference. Liaison Con­ferences coor­dinated the war­time efforts between the Imperial Japa­nese Army and Imperial Japa­nese Navy. In terms of function, it was roughly equiva­lent to the U.S. Joint Chiefs of Staff. Final decisions of Liai­son Conferences were formally disclosed and approved at Imperial Conferences.

Japanese Expansionism Before and During World War II