Sharing a rich history of previous private contacts, official German–Japanese relations started with the first ambassadorial visit in 1860.
Although being traditionally amicable, the two nations' relations have been dynamic and subject to change. After a time of intense educational exchange in the late 19th century, German–Japanese relations cooled due to conflicting hegemonial aspirations, a development which finally climaxed in both states being adversaries during the First World War. In the 1930s, both countries developed mutual interests again and adapted decisively anti-democratic and expansive postures, eventually leading to a re-rapprochement and even a political and military alliance during the Second World War. This "Axis cooperation" was, however, limited by the great geographic distance between South East Asia and Europe as well as a persistent subliminal distrust on both sides. For the most part, Japan and Germany fought separate wars, and eventually had to surrender separately. Nevertheless, the economies of both nations experienced miraculous recoveries after the war and bilateral relations, now focused on economic issues, were swiftly re-established. Today, Japan and Germany are the second and fourth largest economies in the world, respectively, and as such greatly profit from a wide field of political, educational, scientific and economic cooperation.
Relations between Japan and Germany go back to the Edo period (1600–1868), when Germans in Dutch service came to Japan to work for the Dutch East India Company (VOC). The first well-documented cases are those of the physicians Engelbert Kaempfer (1651–1716) and Philipp Franz von Siebold (1796–1866) in the 1690s and the 1820s respectively. Siebold was allowed to travel throughout Japan, in spite of the restrictive seclusion policy the Tokugawa shogunate had implemented since the 1630s. Siebold became the author of Nippon, Archiv zur Beschreibung von Japan (Nippon, Archive For The Description of Japan), one of the most valuable sources of information on Japan well into the 20th century and, since 1979, his achievements are commemorated with a German reward, the Philipp Franz von Siebold-Preis, granted annually to a Japanese scientist.
In 1854, Japan was pressed into the Convention of Kanagawa by the United States. It not only ended Japan's isolation, but was also considered an "unequal treaty" by the Japanese public, since the US did not reciprocate most of Japan's concessions with similar privileges. In many cases Japan was effectively forced in a system of extraterritoriality that provided for the subjugation of foreign residents to the laws of their own consular courts instead of the Japanese law system, open up ports for trade, and later even allow christian missionaries to enter the country. Shortly after the end of Japan's seclusion, in a period called "Bakumatsu" (幕末, "End of the Shogante"), the first German traders arrived in Japan. In 1860, Count Friedrich Albrecht zu Eulenburg led the Eulenburg Expedition to Japan as ambassador from Prussia, one of the most powerful of the numerous regional states in the German Confederation at that time. After four months of negotiations, another "unequal treaty", officially dedicated to amity and commerce, was signed in January 1861 between Prussia and Japan. Only two years later, in 1863, a Shogunal legation arrived at the Prussian court of King Wilhelm I and was greeted with a grandiose ceremony in Berlin. Moreover, immediately after the treaty was signed, Max von Brandt became diplomatic representative in Japan - first of Prussia, then, in 1866, of the North German Confederation and eventually, in 1871, of the newly established German Empire.
In 1868, Japan's process of internal renewal climaxed in the Boshin War, a civil war between the established Tokugawa shogunate and those seeking to return political power to the imperial court and demanding a revocation of the "unequal treaties" with the western powers. During the conflict, German weapons trader Henry Schnell counselled and supplied weapons to the Daimyo of Nagaoka, a land lord loyal to the Shogunate. One year later, the war ended with the defeat of the Shogunate and the formal appointment of Emperor Meiji, marking the beginning of the Meiji period and the renegotiation of the "unequal treaties".
With the start of the Meiji period (1868–1912), many Germans came to work in Japan as advisors to the new government as so called "oyatoi gaikokujin" (お雇い外国人, "hired foreigners") and contributed to the modernization of Japan, especially in the fields of medicine (Leopold Mueller, 1824–1894; Julius Scriba, 1848–1905; Erwin Bälz, 1849–1913), law (K. F. Hermann Roesler, 1834–1894; Albert Mosse, 1846–1925) and military affairs (K. W. Jacob Meckel, 1842–1906). Meckel had been invited by Japan's government in 1885 as an advisor of the Japanese general staff and as teacher at the Army War College. He spent three years in Japan, working with influential persons like Katsura Tarō and Kawakami Soroku, thereby decisively contributing to the modernization of the Imperial Japanese Army. Meckel left behind a loyal group of Japanese admirers, who, after his death, had a bronze statue of him erected in front of his former army college in Tokyo, which was, however, removed in 1945 after the Second World War. Overall, the Imperial Japanese Army intensively oriented its organization along Prusso-German lines when building a modern fighting force during the 1880s. The French model that had been followed by the late shogunate and the early Meiji government was gradually replaced by the Prussian model under the leadership of officers such as Katsura Taro, Nogi Maresuke, and others.
In 1889, the ‘Constitution of the Empire of Japan’ was promulgated, which was greatly influenced by the German legal scholars Rudolf von Gneist and Lorenz von Stein, whom the Meiji oligarch and future Prime Minister of Japan Itō Hirobumi (1841–1909) visited in Berlin and Vienna in 1882. At the request of the German government, also Albert Mosse met with Hirobumi and his group of government officials and scholars and gave a series of lectures on constitutional law convincing him that the Prussian-style monarchical constitution was the best suited for Japan. In 1886, Mosse was invited to Japan on a three-year contract as "hired foreigner" to the Japanese government to assist Hirobumi and Inoue Kowashi in drafting the Meiji Constitution. Afterwards, he worked on other important legal drafts, international agreements, and contracts and served as a cabinet advisor in the Home Ministry, assisting Prime Minister Yamagata Aritomo in establishing the draft laws and systems for local government. Vice versa, dozens of students and military officers went to Germany in the late 19th century in order to study the German military system and receive military training at German army educational facilities and within the ranks of the German, mostly the Prussian army. For example later famous writer Mori Rintarô (Mori Ōgai), who originally was an army doctor, received tutoring in the German language between 1872 and 1874, which was the primary language for medical education at the time. From 1884 to 1888, Ōgai visited Germany and developed an interest in European literature producing the first translations of the works of Goethe, Schiller, Ibsen, Hans Christian Andersen, and Gerhart Hauptmann.
At the end of the 19th century, Japanese–German relations cooled due to Germany’s, and in general Europe's, imperialist aspirations in East Asia. After the conclusion of the First Sino-Japanese War in April 1885, the Treaty of Shimonoseki was signed, which included several territorial cessions from China to Japan, most importantly Taiwan and the eastern portion of the bay of the Liaodong Peninsula including Port Arthur. However, Russia, France and Germany, grew weary of an ever-expanding Japanese sphere of influence and wanted to take advantage of China's bad situation by expanding their own colonial possessions instead. The frictions culminated with the so called "Triple Intervention" on April 23, 1885, when the three powers "urged" Japan to refrain from acquiring its awarded possessions on the Liadong Peninsula. In the following, Wilhelm II’s nebulous fears of a “Yellow Peril” – a united Asia under Japanese leadership, led to further Japanese–German estrangement. Wilhelm II also introduced a regulation to limit the number of members of the Japanese army to come to Germany to study the military system.
Another stress test for German–Japanese relations was the Russo-Japanese War of 1904/05, during which Germany strongly supported Russia, e.g. by supplying Russian war ships with coal. This circumstance triggered the Japanese foreign ministry to proclaim that any ship delivering coal to Russian vessels within the war zone would be sunk. After the Russo-Japanese War, Germany insisted on reciprocity in the exchange of military officers and students, and in the following, several German military officers were sent to Japan to study the Japanese military, which, after its victory over the tsarist army, became a promising organization to study. However, Japan's growing power and influence also caused increased distrust on the German side.
The onset of the First World War in Europe eventually showed how far German–Japanese relations had truly deteriorated. On August 7, 1914, only two days after Great Britain declared war on the German Empire, the Japanese government received an official request from the British government for assistance in destroying the German raiders of the Kaiserliche Marine in and around Chinese waters. Japan, eager to reduce the presence of European colonial powers in South-East Asia, especially on China's coast, sent Germany an ultimatum on August 14, 1914, which was left unanswered. Japan then formally declared war on the German Empire on August 23, 1914 thereby entering the First World War as an ally of Great Britain, France and the Russian Empire to seize the German colonial territories of South-East Asia.
The only major battle that took place between Japan and Germany was the siege of the German-controlled Chinese port of Tsingtao in Kiautschou Bay. The German forces were able to hold out for nearly two months, from August until November 1914, under a total Japanese/British blockade, sustained artillery barrages and manpower odds of 6:1 - a fact that gave a morale boost during the siege as well as later in defeat. After Japanese troops were finally able to occupy the city, the German dead were buried at Tsingtao and the remaining troops were transported to Japan where they were treated well and with respect at places like the Bandō Prisoner of War camp. In 1919, when the German Empire formally signed the Treaty of Versailles, all prisoners of war were set free and returned to Europe.
Japan was one of the signatories of the Treaty, stipulating harsh repercussions for Germany. In the Pacific, Japan gained Germany’s islands north of the equator (the Marshall Islands, the Carolines, the Marianas, the Palau Islands) and Kiautschou/Tsingtao in China. Article 156 of the treaty also transferred German concessions in Shandong to Japan rather than returning sovereign authority to China, an issue soon to be known as Shandong Problem. Chinese outrage over this provision led to demonstrations and a cultural movement known as the May Fourth Movement influenced China not to sign the treaty. China declared the end of its war against Germany in September 1919 and signed a separate treaty with it in 1921. This fact greatly contributed to Germany relying on China, and not Japan, as its strategic partner in East Asia for the coming years.
After Germany had to cede most of former German New Guinea and Kiautschou/Tsingtao to Japan and with an intensifying Sino-German cooperation, relations between Berlin and Tokyo were nearly dead. Under the initiative of Wilhelm Solf, who served as German ambassador to Japan from 1920 to 1928, cultural exchange was strengthened again, culminating in the re-establishment of the "German-Japanese Society" in 1926, the founding of the "Japanese-German Cultural Society" in the following year, as well as the creation of the "Japanese-German Research Institute" in 1934.
Overall - and despite their different fates regarding the First World War - both, Japan and Germany, changed their direction toward democratic systems of government during the 1920s with German–Japanese relations being limited to cultural exchange. However, parliamentary government was not rooted deeply enough in either country and could eventually not withstand the economic and political pressures of the 1930s, during which anti-democratic elements became increasingly influential in both countries. These shifts in power were made possible partly by the ambiguity and imprecision of the Meiji Constitution in Japan and the Weimar Constitution in Germany, especially with regard to the positions of the Japanese Emperor and the German Reichspräsident in relation to their respective constitutions. With the rise of militarism in Japan and Nazism in Germany in the 1930s, political ties between both countries became closer again, amending the already existing cultural exchange. On the Japanese side, particularly army officer Hiroshi Ōshima advocated a closer relationship to Germany and, together with German foreign minister Joachim von Ribbentrop, worked for an alliance when he became military attaché in Berlin in 1934. Over the following decade, Ōshima would then serve twice (1938–39 and 1941–45) as ambassador to Berlin, always remaining one of the strongest proponents of Japan's close partnership with Nazi Germany.
A temporary strain was put on German-Japanese rapprochements in June 1935, when the Anglo-German Naval Agreement was signed between the United Kingdom and Nazi Germany, one of many attempts by Adolf Hitler to improve relations between the two countries. After all, Hitler had already laid down his plans in Mein Kampf, in which he identified England as a promising partner, but also defined Japan as a target of "international jewry", and thus, possible ally:
"It was not in the interests of Great Britain to have Germany annihilated, but primarily a Jewish interest. And to-day the destruction of Japan would serve British political interests less than it would serve the far-reaching intentions of those who are leading the movement that hopes to establish a Jewish world-empire."
At the time, many Japanese politicians, including Admiral Isoroku Yamamoto, who was an outspoken critic of an alliance with Nazi Germany, were shocked by the Anglo-German naval agreement. Nevertheless, the leaders of the military clique then in control in Tokyo concluded that it was a ruse designed to buy the Nazis time to match the British navy.
Tokyo's military leaders proceeded to devise plans assuring the Empire's supply with resources by eventually creating a "Greater East Asia Co-Prosperity Sphere". In general, further expansion was envisioned - either northwards and attacking the Soviet Union, a plan which was called "Hokushin", or by seizing French, Dutch and/or British colonies to the south, a concept dubbed "Nanshin". Hitler on the other hand never desisted from his plan to conquer new "Lebensraum" in Eastern Europe and thus, conflicts with Poland, and then with the Soviet Union seemed inevitable. The first legal consolidation of German-Japanese mutual interests happened in 1936 with the two countries signing the Anti-Comintern Pact directed against the Communist International (Comintern) in general, and the Soviet Union in particular. After the signing, Nazi Germany's government also included the Japanese people in their concept of "honorary Aryans". In 1937, Fascist Italy under Benito Mussolini joined the pact, initiating the formation of the so called Axis between Rome, Berlin and Tokyo ("RoBerTo").
Originally Germany had a very close relationship with the Chinese nationalist government, even providing military aid and assistance to the Republic of China. Relations soured after the outbreak of the Second Sino-Japanese War on July 7, 1937, and when China shortly later concluded the Sino-Soviet Non-Aggression Pact with the Soviet Union. Eventually Hitler concluded that Japan, not China, would be a more reliable geostrategic partner, notwithstanding the superior Sino-German economic relationship and chose to end the alliance with the Chinese as the price of gaining an alignment with the more modern and powerful Japan. In an address to the Reichstag in May 1938, Hitler announced German recognition of Manchukuo, the Japanese-occupied puppet state in Manchuria, and renounced the German claims to the former colonies in the Pacific held by Japan. Hitler ordered an end to arm shipments to China, and ordered the recall of all the German officers attached to the Chinese Army. Despite this move, however, Hitler retained his general perception of neither the Japanese nor the Chinese civilizations being inferior to the German one. In The Political Testament of Adolf Hitler, Hitler would later state:
"Pride in one's own race - and that does not imply contempt for other races - is also a normal and healthy sentiment. I have never regarded the Chinese or the Japanese as being inferior to ourselves. They belong to ancient civilizations, and I admit freely that their past history is superior to our own. They have the right to be proud of their past, just as we have the right to be proud of the civilization to which we belong. Indeed, I believe the more steadfast the Chinese and the Japanese remain in their pride of race, the easier I shall find it to get on with them."
In 1938, representative measures for embracing the German-Japanese partnership were sought and the construction of a new Japanese embassy building in Berlin was started. 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. It was conceived by Ludwig Moshamer under the supervision of Speer and was located right opposite to the embassy of Italy, Germany's closest ally, thereby bestowing an architectural emphasis on the Rome-Berlin-Tokyo axis.
Despite tentative plans for a joint German-Japanese approach against the USSR were slowly maturing and regardless of the still young Anti Comintern Pact of 1936, the years 1938 and 1939 were already decisive for Japan's decision to finally expand south- and not northwards. The Empire decisively lost two border fights against the Soviets, the Battles of Lake Khasan and Khalkin Gol, thereby convincing that the Japanese Imperial Army, lacking heavy tanks and the like, would be in no position to challenge the Red Army for the time being. Nevertheless, Hitler's anti-Soviet sentiment soon led to further rapprochements with Japan, since he still believed it would join Germany in a future war against the Soviet Union - either actively by invading South-East Siberia, or passively by binding large parts of the Red Army, which was fearing an attack of Japan's Kwantung Army in Manchukuo, numbering ca. 700,000 men as of the late 1930s.
In contrast to his actual plans, Hitler's concept of stalling - in combination with his frustration of a reluctant Japan embroiled in seemingly perpetual negotiations with the United States and tending against a war with the USSR - led to a temporary cooperation with the Soviets in form of the so called Molotov–Ribbentrop Pact signed in May 1939. Neither Japan, nor Italy, had been previously informed of Germany's pact with the Soviets, demonstrating the constant subliminal mistrust between Nazi Germany and its partners. After all, the pact not only stipulated the division of Poland between both signatories in a secret protocol, but also rendered the Anti-Comintern Pact more or less irrelevant. In order to remove the strain Hitler's move has put on German–Japanese relations, the "Agreement for Cultural Cooperation between Japan and Germany" was signed in November 1939, only a few weeks after Germany and the Soviet Union had concluded their invasion of Poland and Great Britain and France declared war on Nazi Germany.
Over the following year, Japan proceeded with its expansion plans, too. The Invasion of French Indochina on 2 September 1940, which had by then been under the control of the newly established German puppet-state of Vichy France, stated their preliminary climax and, together with Japan's ongoing bloody conflict with China, put a severe strain on American-Japanese relations. On July 26, 1940, the U.S. had already passed the Export Control Act, cutting oil, iron and steel exports to Japan. This containment policy was seen by Washington as a warning to Japan that any further military expansion would result in further sanctions. However, it would be exactly this stance strengthening Tokyo's propononents of taking radical measures to improve the Empire's situation, thereby driving Japan closer to Germany.
As the Empire of Japan was beginning to seek a final solution, either diplomatic or military, with regard to its deteriorating relations with the US, and Nazi Germany not only conquered most of continental Europe including France, but also managed to keep up the false picture of Britain being about to be defeated, Tokyo interpreted the situation in Europe as a fundamental and fatal weakness of the western democracies. Japan's leadership concluded that the current state of affairs had to be exploited and subsequently started to seek an intensification of its cooperation with Berlin. Hitler on the other side not only feared a lasting stalemate with Great Britain, but also began devising a plan for an invasion of the Soviet Union. These circumstances, together with a shortage in raw materials and food, increased Berlin's interest in a stronger alliance with Japan. The German foreign minister Joachim von Ribbentrop was sent to negotiate a new treaty with Japan, whose relationships with Germany and Italy, which were soon to be called "Axis powers", were cemented with the signature of the Tripartite Pact on 27 September 1940.
The purpose of the pact, which was directed against an unnamed power that was clearly meant to be the United States, was to deter the Americans from supporting the UK, thereby not only strengthening Germany's and Italy's cause in the North African Campaign and the Mediterranean theatre, but also weakening Great Britain's colonies in South-East Asia in advance of a Japanese invasion. The treaty also demonstrated that the three countries would respect each other's strategic aims in dominating their respective spheres of influence, and would be obliged to assist each other in the case a member state was attacked by a third party. However, already ongoing conflicts as of the signing of the pact had been explicitly excluded. Furthermore, with this defensive stance, aggressive moves on the part of a member state resulted in no pact-obligations. After all, relations between the two wartime Axis members Germany and Japan were directed through mutual self-interest, underpinned to some degree by the shared militarist, expansionist and nationalistic ideologies of both governments.
Another decisive limitation in the German-Japanese alliance were the fundamental differences between the two nation's policies towards Jews. With Nazi Germany's well-known attitude being extreme anti-Semitic, Japan refrained from adapting any similar posture. On December 31, 1940, Japanese foreign minister and convinced proponent of the Tripartite Pact with the Third Reich and Fascist Italy, Yōsuke Matsuoka, told a group of Jewish businessmen:
As a matter of fact, until 1945, both countries would continue to conceal any war crimes committed by the other side from its population in order to prevent each other's images being compromised in any way. The Holocaust was systematically concealed by the leadership in Tokyo, just like Japanese war crimes, e.g. the situation in China, were kept secret from the German population. One popular example are the atrocities committed by the Japanese Army in Nanking in 1937 which were denounced by the German industrialist John Rabe. Subsequently, the German leadership ordered Rabe back to Berlin, confiscating all his reports and prohibiting any further discussion of the topic.
After the signing of the Tripartite Pact, not only mutual visits of political, but also of military background increased. After German ace and parachute expert, Ernst Udet, visited Japan in 1939 to inspect the Japanese Air Force and then reporting to Hermann Göring that "Japanese flyers, though brave and willing, were no sky-beaters", General Tomoyuki Yamashita was given the job of reorganizing the Japanese Air Force in late 1940. For this purpose, Yamashita arrived in Berlin in January 1941, staying almost six months with a tight schedule: Inspecting the broken Maginot Line and German fortifications on the French coast, watching German flyers in training and even flying in a raid over Britain after decorating Hermann Göring, head of the German Luftwaffe, with the Japanese "Grand Cordon of the Rising Sun". General Yamashita also met and talked with Hitler, on whom he commented:
"I felt, that in the mind of Hitler there was much of spiritual matters, transcending material plans. When I met the Führer he said that since boyhood he had been attracted by Japan. He read carefully reports of Japan's victory over Russia when he was only 17 years old and was impressed by Japan's astonishing strength."
According to Yamashita, Hitler allegedly promised to remember Japan in his will, by instructing the Germans "to bind themselves eternally to the Japanese spirit." In fact, General Yamashita was so excited that he said: "In a short time, something great will happen. You just watch and wait." On its return home, the Japanese delegation was accompanied by more than 250 German technicians, engineers and instructors and soon, Japan's Air Force belonged to the most powerful in the world.
In order to directly or indirectly support his imminent invasion of the Soviet Union, Hitler had repeatedly urged Japan to enter the war throughout 1940 and 1941. 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 broadly hinted at, but never openly asked for, either invading the Soviet Union from the east or by 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. Although Germany would have clearly favored Japan attacking the USSR, exchanges between the two allies were always kept overly formal and indirect, as it is shown in the followng statement by Hitler towards ambassador Ōshima from 2 June 1941:
"It would, of course, be up to Japan to act as it saw fit, but Japan's cooperation in the fight against the Soviet Union would be welcomed if the [Japanese] advance to the south should run into difficulty because of supply and equipment."
Matsuoka, Ōshima and parts of the Japanese Imperial Army were proponents of "Hokushin", Japan's go north strategy aiming for a coordinated attack with Germany against the USSR and seizing East Siberia. But the Japanese army-dominated military leadership, namely persons like minister of war Hideki Tōjō, were constantly pressured by the Japanese Imperial Navy and, thus, a strong tendency towards "Nanshin" existed already in 1940, meaning to go south and exploiting the weakened European powers by occupying their resource-rich colonies in South-East Asia. In order to secure Japan's back while expanding southwards and as a Soviet effort to demonstrate peaceful intentions toward Germany, the Soviet–Japanese Neutrality Pact was signed on 13 April 1941. Hitler, considering the pact a ruse to stall, misenterpreted the diplomatic situation and thought that his attack on the USSR would bring a tremendous relief for Japan in East Asia and thereby a much stronger threat to American activities through Japanese interventions. As a consequence, Nazi Germany pressed forward with Operation Barbarossa, its attack on the Soviet Union, which started two months later on 22 June and without any specific warning to its Axis partners.
Ironically, Stalin had little faith in Japan's commitment to neutrality even before the German attack, but he felt that the pact was important for its political symbolism, to reinforce a public affection for Germany. From Japan's point of view the attack on Russia very nearly ruptured the Tripartite Pact on which the Empire was depending for Germany's aid 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 of Barbarossa, even though he had feared the worst since receiving an April report from Ōshima in Berlin that "Germany is confident she can defeat Russsia and she is preparing to fight at any moment." Foreign minister Matsuoka on the other hand vividly tried to convince the Emperor, the cabinet as well as the army staff of an immediate attack on the Soviet Union. However, his colleagues rejected any such proposal, even regarding him as "Hitler's office boy" by now and pointed out to the fact that the Japanese army, with its light and medium tanks, had no intention of taking on Soviet tanks and aircraft until they could be certain that the Wehrmacht had smashed the Red Army to the brink of defeat. Subsequently, Konoe removed Matsuoka from his cabinet and stepped up Japan's negotiations with the US again, which still failed over the China and Indochina issues, however, and the American demand to Japan to withdraw from the Tripartite Pact in anticipation of any settlement. Without any perspective with respect to Washington, Matsuoka felt that his government had to reassure Germany of its loyalty to the pact. In Berlin, Ōshima was ordered to convey to the German foreign minister Ribbentrop that the "Japanese government have decided to secure 'points d'appui' in French Indochina to enable further to strengthen her pressure on Great Britain and the Unites States of America," and to present this as a "valuable contribution to the common front" by promising:
"We Japanese are not going to sit on the fence while you Germans fight the Russians."
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. 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 eventually transmitted information that Japan was not going to start hostilities against the USSR in the East, thereby freeing Red Army divisions stationed in Siberia for the defence of Moscow.
In September 1941, Japan took its first step for a southward expansion by expanding its military presence in Indochina ("securing 'points d'appui'") and decisively increased the number of stationed personnel and planes. This, however, provoked the United States, the United Kingdom, and other Western governments to freeze Japanese assets, while the US (which supplied 80 percent of Japan's oil) responded by placing a complete oil embargo on the Japanese Empire. As a result, Japan was essentially forced to choose between abandoning its ambitions in South-East Asia and the prosecution of the war against China, or seizing the natural resources it needed by force. 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 at the Battle of Khalkin Gol in 1939 and the final rejection of any near-term action in Siberia shortly after Germany began its invasion of the USSR. Moreover, many officers considered America's oil embargo an unspoken declaration of war. With the harsh oil sanctions imposed by the United States, the Japanese leadership was now even more determined to prevent its industry, including its mighty navy, from starving by capturing the oil fields of the Netherlands Indies. As such a course of action was guaranteed to provoke an American declaration of war, the decision for a pre-emptive strike to deprive the US of their only means of pressure against Japan, the United States Pacific Fleet, was settled.
On November 25, Germany tried to further solidify the alliance against Soviet Russia by officially reviving the Anti-Comintern Pact of 1936, now joined by additional signatories like Hungary and Romania. However, with the Soviet troops around Moscow now being reinforced by East Siberian divisions, Germany's offensive substantially slowed with the onset of the Russian winter in November and December 1941. In the face of his failing Blitzkrieg tactics, Hitler's confidence in a successful and swift conclusion of the war diminished, especially with an US-supported Britain being a constant threat in the Reich's rear. Furthermore, the fact that the neutrality the US have superficially kept up so far would soon change to an open and unlimited support of their unofficial British ally against Germany became more and more obvious. Hitler thus welcomed Japan's sudden entry into the war with its air raid on the American naval base at Pearl Harbor on 7 December 1941 and its subsequent declaration of war on the United States and Britain, just as the German army suffered its first military defeat at the gates of Moscow. Right after hearing of Japan's successful attack, Hitler even got euphoric and stated: "With such a capable ally we cannot lose this war." Preceding Japan's attack were numerous communiqués between Berlin and Tokyo. The respective ambassadors Ott and Ōshima tried to draft an amendment to the Tripartite Pact, in which Germany, Japan and Italy should pledge each other's allegiance in the case one signatory is attacked by - or attacks - the United States. Although, the protocol was finished in time, it would not be formally signed by Germany until four days after the raid on Pearl Harbor. Also part of the communiqués was another definitive Japanese rejection of any war plans against Russia:
"In case Germany demands that we participate in the war against the Soviet Union, we will respond that we do not intend to join the war for the time being. If this should lead to a situation whereby Germany will delay her entry into the war against the United States, it cannot be helped."
Nevertheless, publicly, the German leadership applauded their new ally and ambassador Ōshima became one of only eight recipients of the Grand Cross of the Order of the German Eagle in Gold, which was awarded by Hitler himself, who reportedly said:
"You gave the right declaration of war. This method is the only proper one. Japan pursued it formerly and it corresponds with his own system, that is, to negotiate as long as possible. But if one sees that the other is interested only in putting one off, in shaming and humiliating one, and is not willing to come to an agreement, then one should strike as hard as possible, and not waste time declaring war."
Moreover, even with the afore mentioned amendment to the Tripartite Pact not being in force yet, Hitler chose to declare war on the United States and ordered the Reichstag, along with Italy, to do so on December 11, 1941, three days after the United States' declaration of war on the Empire of Japan. His hopes that, despite the previous rejections, Japan would reciprocally attack the Soviet Union after all did not transpire, however, since Japan sticked to its Nanshin strategy of going south, not north, and would continue to maintain an uneasy peace with the Soviet Union until 1945. Nevertheless, Germany's declaration of war further solidified German–Japanese relations and showed Germany's solidarity with Japan, which was now encouraged to cooperate against the British. To some degree, Japan's actions in South-East Asia and the Pacific, like the sinking of the HMS Prince of Wales and the HMS Repulse in addition to the subsequent occupation of the Crown Colonies of Singapore and Hong Kong as well as British Burma, not only stated a tremendous blow to the United Kingdom's war effort, but would preoccupy 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. In this context, sizeable Australian and British forces were withdrawn from North Africa to the Pacific theater with their replacements being only relatively inexperienced and thinly spread divisions. 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. In the long run, Germany and Japan envisioned a partnered linkage running across the British-held Indian subcontinent that would allow for the transfer of weaponry, resources as well as other possibilities. 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.
Until Germany attacked the Soviet Union, the two countries were able to exchange these materials using the Trans-Siberian Railway, but after the attack submarines had to be sent on so called "Yanagi" (Willow) - missions, since the American and British navies rendered the high seas too dangerous for any cargo ships. However, given the limited capacities of submarines, eyes were soon focused directly on the Mediterranean, the Middle East and British India, all vital to the British war effort. Most importantly, though, the latter two were also offering a direct land-linkage between the Third Reich and Japan able to improve trade possibilities and enabling potential joint military operations. However, and despite an initial shift of their attention, the Allies never abandoned their "Germany first" policy throughout the war, stipulating that Nazi Germany should be defeated before the focus is shifted to Japan, thereby putting and end to Hitler's advances in that direction, which should never pass Egypt and the Caucasus. Additionally, Japan's invasion of India already halted in Burma, rendering any decisive joint operations, aside from the German U-boat flotilla "Monsun Gruppe" cooperating with the Japanese Navy in the Indian Ocean, impossible. With submarines staying the only link between Nazi-controlled Europe and Japan, trade was soon focused on strategic goods like technical plans, weapon templates and the like. Nevertheless, only 20 to 40% of goods ever managed to reach either destination and merely 96 persons traveled by submarine from Europe to Japan and 89 vice versa during the war as only six submarines succeeded in their attempts of the trans-oceanic voyage: I-30 (April 1942), I-8 (June 1943), I-34 (October 1943), I-29 (November 1943), I-52 (March 1944), and the German submarine U-511 (August 1943). U-234 on the other hand is one of the most popular examples of an aborted Yanagi mission in May 1945.
Relations between Japan and Axis ally Vichy France, which controlled strategically important French Indochina, were significantly worse and the two sides even briefly fought each other on two occasions; once when Japan reneged on the conditions concerning Japanese troops being stationed in Vichy territory (just prior to the signing of the Tripartite Pact in 1940), and once in 1945. Germany did not get involved in either situation, which again showed the largely passive and defensive character of the German-Japanese alliance.
As the war progressed and Germany began to retreat, Japanese ambassador Ōshima never wavered in his confidence that Germany would emerge victorious. However, in March 1945 he reported to Tokyo on the "danger of Berlin becoming a battlefield" and revealing a fear "that the abandonment of Berlin may take place another month". On 13 April, 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 had to leave Berlin at once by Hitler's direct order. On May 7 and 8, 1945, as the German government surrendered to the Allied powers, Ōshima and his staff were taken into custody and brought to the United States. Now fighting an even more hopeless war, the Japanese government immediately denounced the German surrender as an act of treason and interned the few German individuals as well as confiscated all German property (such as submarines) in Japanese territory at the time. Four months later, on September 2, Japan had to sign its own surrender documents.
After their defeat in World War II, both Japan and Germany were occupied. While Japan could regain its sovereignty with the Treaty of San Francisco in 1952 and joined the United Nations in 1956, Germany was split into two states, which were both founded in 1949. The Federal Republic of Germany (West Germany) restored diplomatic ties with Japan in 1955, the German Democratic Republic as late as 1973, the year both German states became UN-members.
Quickly, academic and scientific exchange was strengthened, and in 1974, West Germany and Japan signed an intergovernmental agreement on cooperation in science and technology, re-intensifying joint scientific endeavours and technological exchange. The accord resulted in numerous bilateral cooperations since then, generally focused on marine research and geosciences, life sciences and environmental research.
German-Japanese political exchange further intensified again with both countries taking part in the creation of the so called Group of Six, or simply "G6", together with the US, the UK, France and Italy in 1975 as a response to the 1973 oil crisis. The G6 was soon expanded by Canada and later the Russian Federation, with G6-, G7-, and later G8-, summits being held annually since then.
Over the following years, institutions, such as in 1985 the "Japanese–German Center" (JDZB) in Berlin and in 1988 the "German Institute for Japanese Studies" (DIJ) in Tokyo, were founded to further contribute to the academic and scientific exchange between Japan and Germany.
In general, however, post-war relations between Japan and both halves of Germany, as well as with unified Germany after 1990, have focused on economic questions, and as such, Germany, dedicated to free trade, continues to be Japan’s largest trading partner within Europe until today. This general posture is also reflected in the so called "7 pillars of cooperation" agreed on by Foreign Minister of Japan Yōhei Kōno and Foreign Minister of Germany Joschka Fischer on October 30, 2000:
In 2000, bilateral cultural exchange culminated in the "Japan in Germany" year, which was then followed by the "Germany in Japan" year in 2005/2006.
In 2004, German Chancellor Gerhard Schröder and Japanese Prime Minister Junichiro Koizumi agreed upon cooperations in the assistance for reconstruction of Iraq and Afghanistan, the promotion of economic exchange activities, youth and sports exchanges as well as exchanges and cooperation in science, technology and academic fields.
In the late 1990s and early 2000s, Germany and Japan, being the United Nation's second and third largest funders respectively, demanded a reform of the United Nations Security Council and an increase of the number of its permanent members. For this purpose both nations organized themselves together with Brazil and India to form the so called "G4 nations". On 21 September 2004, the G4 issued a joint statement mutually backing each other's claim to permanent seats, together with two African countries. This proposal has found opposition in a group of countries called Uniting for Consensus. In January 2006, Japan announced that it would not support putting the G4 resolution back on the table and was working on a resolution of its own.
Today, Japan is Germany's second largest trading partner in Asia after China. In 2006, German imports from Japan totaled €15.6 billion and German exports to Japan €14.2 billion (15.4% and 9% more than the previous year, respectively). In 2008, however, Japanese exports and imports to and from the European Union fell by 7.8 and 4.8% after growing by 5.8% in 2007 due to the global financial crisis. Bilateral trade between Germany and Japan also shrank in 2008, with imports from Japan having dropped by 6.6% and German exports to Japan having declined by 5.5%. Despite Japan having remained Germany's principal trading partner in Asia after China in 2008, measured in terms of total German foreign trade, Japan’s share of both exports and imports is relatively low and falls well short of the potential between the world’s second- and fourth-largest economies.
On the 14th and 15th of 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. Westerwelle emphasized, that
"We want to make our joint contribution towards ensuring that this decade is a decade of disarmament – not a decade of armament"
and both ministers instructed their Ministries to draw up disarmament initiatives and strategies which Berlin and Tokyo can present to the international community together. Especially with regard to Iran's nuclear program, it was also stressed that Japan and Germany, both technical capable to and yet refraining from possessing any ABC weapons, should assume a leading role in realizing a world free of nuclear weapons and that international sanctions are considered to be an appropriate instrument of pressure. Furthermore, Westerwelle and Okada agreed to enhance cooperation in Afghanistan and to step up the stagnating bilateral trade between both countries. The visit was concluded in talks with Japan's Prime Minister Yukio Hatoyama, before which the German foreign minister visited the famous Meiji Shrine in the heart of Tokyo.