[5] Despite being considered one of the numerous unjust negotiations pressed on Japan during that time, the Eulenburg Expedition, and both the short- and long-term consequences of the treaty of amity and commerce, are today honoured as the beginning of official Japanese-German relations.

In general, further expansion was envisioned – either northwards, attacking the Soviet Union, a plan which was called Hokushin-ron, or by seizing French, Dutch and/or British colonies to the south, a concept dubbed Nanshin-ron.

After the preceding embassy had to give way to Hitler's and Albert Speer's plans of re-modeling Berlin to the world capital city of Germania, a new and more pompous building was erected in a newly established diplomatic district next to the Tiergarten.

[28] In contrast to his actual plans, Hitler's concept of stalling – in combination with his frustration with a Japan embroiled in seemingly endless negotiations with the United States, and tending against a war with the USSR[36] – led to a temporary cooperation with the Soviets in the Molotov–Ribbentrop Pact, which was signed in August 1939.

The Invasion of northern French Indochina on 22 September 1940 (which by then was controlled by the collaborating government of Vichy France), and Japan's ongoing bloody conflict with China, put a severe strain on Japan–United States relations.

German foreign minister Joachim von Ribbentrop was sent to negotiate a new treaty with Japan, whose relationships with Germany and Italy, the three soon to be called "Axis powers", were cemented with the Tripartite Pact of 27 September 1940.

On 31 December 1940, Japanese foreign minister Yōsuke Matsuoka, a strong proponent of the Tripartite Pact, told a group of Jewish businessmen: I am the man responsible for the alliance with Hitler, but nowhere have I promised that we would carry out his anti-Semitic policies in Japan.

On 11 November 1940, German–Japanese relations, as well as Japan's plans to expand southwards into South-East Asia, were decisively bolstered when the crew of the German auxiliary cruiser Atlantis boarded the British cargo ship SS Automedon.

Japan wishes, if possible, to avoid war against the U.S.A. She can do so if she determinedly takes Singapore as soon as possible.In talks involving Hitler, his foreign minister Joachim von Ribbentrop, his Japanese counterpart at that time, Yōsuke Matsuoka, as well as Berlin's and Tokyo's respective ambassadors, Eugen Ott and Hiroshi Ōshima, the German side then broadly hinted at, but never openly asked for, either invading the Soviet Union from the east or attacking Britain's colonies in South-East Asia, thereby preoccupying and diverting the British Empire away from Europe and thus somewhat covering Germany's back.

In order to secure Japan's back while expanding southwards and as a Soviet effort to demonstrate peaceful intentions toward Germany,[52] the Soviet–Japanese Neutrality Pact was signed in Moscow on 13 April 1941 by Matsuoka on his return trip from a visit to Berlin.

From Japan's point of view the attack on Russia very nearly ruptured the Tripartite Pact, since the Empire had been depending on Germany to help in maintaining good relations with Moscow so as to preclude any threat from Siberia.

Prime Minister Fumimaro Konoe felt betrayed because the Germans clearly trusted their Axis allies too little to warn them about Barbarossa, even though he had feared the worst since receiving an April report from Ōshima in Berlin that "Germany is confident she can defeat Russia and she is preparing to fight at any moment."

"[36] Over the first months, Germany's advances in Soviet Russia were spectacular and Stalin's need to transfer troops currently protecting South-East Siberia from a potential Japanese attack to the future defense of Moscow grew.

Japan's Kwantung Army in Manchukuo was constantly kept in manoeuvres and, in talks with German foreign minister Ribbentrop, ambassador Oshima in Berlin repeatedly hinted at an "imminent Japanese attack" against the USSR.

[54] Unknown to Japan and Germany, however, Richard Sorge, a Soviet spy disguised as a German journalist working for Eugen Ott, the German ambassador in Tokyo, advised the Red Army on 14 September 1941, that the Japanese were not going to attack the Soviet Union until: Toward the end of September 1941, Sorge transmitted information that Japan would not initiate hostilities against the USSR in the East, thereby freeing Red Army divisions stationed in Siberia for the defence of Moscow.

The Japanese military did not consider the former an option as attacking Soviet Russia instead of expanding into South Asia had become a more and more unpopular choice since Japan's humiliating defeat in 1939 at the Battle of Khalkin Gol against General Georgy Zhukov amongst others and the final rejection of any near-term action in Siberia shortly after Germany began its invasion of the USSR.

[62] However, for several reasons including logistics and Soviet defenses being reinforced by East Siberian divisions, Germany's offensive on Moscow ground to a halt with the onset of the Russian winter in November and December 1941.

To some degree, Japan's actions in South-East Asia and the Pacific in the months after Pearl Harbor, including the sinking of HMS Prince of Wales and HMS Repulse, the occupation of the Crown Colonies of Singapore, Hong Kong, and British Burma, and the raids in the Indian Ocean as well as on Australia, were a tremendous blow to the United Kingdom's war effort and preoccupied the Allies, shifting British (including Australian) and American assets away from the Battle of the Atlantic and the North African Campaign against Germany to Asia and the Pacific against Japan.

Taking advantage of this situation, Erwin Rommel's Afrika Korps successfully attacked only six weeks after Pearl Harbor, eventually pushing the allied lines as far east as El Alamein.

After all, the choice of potential trading partners was very limited during the war and Germany was anxious for rubber and precious metals, while the Japanese sought industrial products, technical equipment, and chemical goods.

[29] By August 1942 the German advances in North Africa rendered an offensive against Alexandria and the Suez Canal feasible, which, in turn, had the potential of enabling maritime trade between Europe and Japan through the Indian Ocean.

On the other hand, in the face of its defeat at the Battle of Midway in June 1942 with the loss of four aircraft carriers, the Japanese Navy decided to pursue all possibilities of gaining additional resources to quickly rebuild its forces.

As a consequence, Ambassador Ōshima in Berlin was ordered to submit an extensive "wish list" requesting the purchase of vast amounts of steel and aluminium to be shipped from Germany to Japan.

"[78] Japan, on the other hand, not only evaded any disclosure of its true strategic position in the Pacific, but also declined any interference in American shipments being unloaded at Vladivostok and large numbers of men and amounts of material being transported from East Siberia to the German front in the west.

Being forced to watch the continued reinforcement of Soviet troops from the east without any Japanese intervention was a thorn in Hitler's flesh, especially considering Japan's apparent ignorance with respect to the recent Casablanca Conference at which the Allies declared only to accept the unconditional surrenders of the Axis nations.

Here it was the goal of the Allied prosecutors to portray the limited cooperation between the Third Reich and Imperial Japan as a long-planned conspiracy to divide the world among the two Axis-partners and thereby delivering just another demonstration of the common viciousness expressed by alleged joint long-term war plans.

On 14 and 15 January 2010, German foreign minister Guido Westerwelle conducted his personal inaugural visit to Japan, focusing the talks with his Japanese counterpart, Katsuya Okada, on both nation's bilateral relations and global issues.

[119] On 2 April 2011, German Foreign Minister Westerwelle visited Tokyo on an Asia voyage, again offering Japan "all help, where it is needed" to recover from the tsunami and subsequent nuclear disaster of the previous month.

Together with his German counterpart, Japanese foreign minister Takeaki Matsumoto also addressed potential new fields of cooperation between Tokyo and Berlin with respect to a reform of the United Nations Security Council.

Dettmar Cramer, who was invited as a coach to strengthen the Japanese men's national team in preparation for the 1964 Tokyo Olympics, which led Japan to the top eight at the tournament, and key players such as Kunishige Kamamoto, who received his guidance, also participated.