Fragment of an actual Purple machine from the Japanese embassy in Berlin, obtained by the United States at the end of World War II. The photograph in the display shows Hiroshi Oshima shaking hands with Adolf Hitler. Joachim von Ribbentrop stands in the middle.
Adolf Hitler meeting with Hiroshi Oshima
l.t.r. Olga Bjoner, Gertrud Scholtz-Klink, Mrs. Oshima, Pilar Primo de Rivera and Olga Medici in 1941
Oshima graduated from the 18th class of the Imperial Japanese Army Academy in June 1905 and was promoted to second lieutenant in June 1906 and to lieutenant in June 1908.
He graduated from the 27th class of the Army War College in May 1915, and was promoted to captain the following year.
From 1918-1919, he served in Siberia with the expeditionary forces, and was appointed assistant military attaché in the Japanese embassy to the Weimar Republic. Promoted to major in January 1922, he served as a military attaché to Budapest and Vienna from 1923-1924. After his return to Japan, he was promoted to lieutenant colonel in August 1926, following a promotion to colonel in August 1930, he served as commander of the 10th Field Artillery Regiment from 1930-1931.
In 1934, Colonel Oshima became Japanese military attaché in Berlin. He spoke almost perfect German, and was soon befriended by Joachim von Ribbentrop, who was Adolf Hitler's favorite foreign policy advisor at that time. Although Hitler ostensibly used the Foreign Ministry (Auswärtiges Amt) for his foreign relations, he was in fact more dependent on the Dienststelle Ribbentrop, a competing foreign office operated by the ex-champagne salesman.
Promoted to major general in March 1935, under Ribbentrop's guidance, Oshima met privately with Hitler that fall. With the support of the Nazi leadership and the Imperial Japanese Army General Staff, Oshima progressed rapidly while in Berlin, attaining the rank of lieutenant general and being appointed ambassador to Berlin in October 1938, upon which he entered the reserves. During his early months as an ambassador, according to evidence presented later at the Nürnberg Trial of Major War Criminals, he was plotting the assassination of Joseph Stalin through Russian agents who were sympathetic to his cause. In a conversation Oshima had with Heinrich Himmler on 31 January 1939, he expressed the hope that German-Japanese cooperation in the field of intelligence would lead eventually to the disintegration of the Soviet Union.
In September 1939, Oshima was recalled to Japan as relations between the German and Japanese governments were strained following the conclusion of the German-Soviet non-aggression pact - returning via the United States. Upon the insistence of the Nazi government, he returned to Berlin as Japanese Ambassador in February 1941, and remained in that position until the German surrender in May 1945.
Oshima made visits to the Eastern Front and the Atlantic Wall, and he met periodically with Hitler and other Nazi leaders. Being a meticulous military officer in training, he wrote detailed reports of the information provided to him by the Nazis - and promptly reported by radio to Tokyo in the Purple diplomatic cipher. Unknown to the Japanese, the PURPLE code was broken by American codebreakers in 1940, thus Oshima's reports were being read almost simultaneously by those who had access to Magic intelligence. Often, they were able to read them before the Japanese did, as transmission problems between Germany and Japan often held up the cables for hours.
Virtually all of Ōshima's dispatches were intercepted: approximately 75 during the 11 months of 1941, some 100 in 1942, 400 in 1943, 600 in 1944, and about 300 during the just over four months of 1945 when Germany was at war. This despite the fact that the Germans often reproached him of the unreliability of the Japanese codes, although Oshima assured them of its security.
As the war progressed and Germany began to retreat, Oshima never wavered in his confidence that Germany would emerge victorious. On 13 April 1945, he met with Ribbentrop - for the last time, it turned out - and vowed to stand with the leaders of the Third Reich in their hour of crisis. But he was informed that evening by the Foreign Ministry's chief of protocol: all diplomats were to leave Berlin at once by Hitler's direct order.
Less than a month later Germany surrendered and Oshima and his staff were taken into custody. They were brought to the United States by ship, arriving on 11 July 1945. After interrogation and internment in Bedford Springs Hotel, a resort hotel in the heart of the Allegheny Mountains, Pennsylvania, Oshima was returned to Japan in November 1945.
Although he enjoyed freedom briefly in his devastated country, he was arrested on 16 December 1945 and charged with war crimes. When brought before the International Military Tribunal for the Far East, he was found guilty of conspiring to wage aggressive war on 12 November 1948 and sentenced to life imprisonment. Oshima was paroled in late 1955 and granted clemency three years later. Oshima died in 1975, not knowing that he provided the Allies with invaluable intelligence during the war.