Japanese-German Naval Collaboration in World War II*

In retrospect it is interesting to compare the opinions and fears expressed during the early days of disaster following the attack upon Pearl Harbor, with the actual situation as it was then developing on the enemy side. For example, it will be recalled that many persons in 1942 feared a junction of Japanese and German forces in the Indian Ocean region or in the Middle East. Such a junction would ultimately have involved the question of full scale Japanese- German collaboration, and would have gravely threatened Allied victory. Actually, however, these Axis partners were not prepared for effective collaboration between themselves, in marked contrast to the favorable working arrangements which developed among the Allied Powers.

Such collaboration between Japan and Germany as was undertaken during the war was largely in the field of naval operations. An examination of the record of this collaboration, however, demonstrates clearly the fundamental weaknesses of the Axis alliance itself, based as it was upon opportunism and mutual distrust. Italy, the third member of the Axis until her surrender in 1943, may be omitted for the most part from this discussion, since she was treated virtually as an occupied country by Germany, and there appears to have been no serious consideration of cooperation between the Japanese and Italian navies.

The Axis Alliance

Naval collaboration between Japan and Germany was derived from political arrangements. The partnership of the two powers was established formally in November, 1936, with the signing in Berlin of the Anti-Comintern Pact. This agreement was directed toward the activities of the Communist International. The two signatories promised to “keep each other informed concerning the activities of the Communist International,” to “confer upon the necessary measures for defense,” and to “carry out such measures in close cooperation.”

One year later Italy adhered to the Anti- Comintern Pact. This event in effect extended the already-established Rom e-Berlin Axis to Tokyo, and signalized the alliance of the three totalitarian powers. Although the Anti-Comintern Pact continued to be directed nominally against the Soviet Union and the Soviet form of government, the purpose of the alliance was much broader. The situation was well summarized in a dispatch from Ambassador Joseph C. Grew to Washington dated November 13, 1937. “If the present triangular combination is analyzed,” the Ambassador explained, “it becomes immediately apparent that not only is the group not merely anticommunist, but that its policies and practices equally run counter to those of the so-called democratic powers. Thus it can be seen that the question resolves itself into the simple fact that it is a combination of those states which are bent upon upsetting the status quo as opposed to those states which wish to preserve the status quo, or, more simply, of the ‘have- nots’ against the ‘haves,’ and that anti-communism is merely the banner under which the ‘have-nots’ are rallying. The threat to England is very real and immediately apparent upon reflection that the life-line of the British Empire is threatened from the North Sea through the Mediterranean and beyond Singapore.”

Following the outbreak of World War II in 1939 the Axis partners were brought closer together. Japan took advantage of the preoccupation of Great Britain and the United States with affairs in Europe to push forward in her attempt to establish hegemony in the Far East. Following the German victories in Europe, in September, 1940 Japan, Germany, and Italy signed the Three Power Treaty, a ten year alliance pledging mutual support in the establishment of a new order in Europe and Asia. Under the terms of this agreement Japan recognized and respected the leadership of Germany and Italy in the establishment of a new order in Europe, and Germany and Italy correspondingly recognized and respected the leadership of Japan in East Asia. According to Article 3 of the Treaty the three parties agreed “to cooperate in their efforts on the aforesaid lines,” and they further undertook “to assist one another with all political, economic, and military means when one of the three Contracting Parties is attacked by a power at present not involved in the European war or in the Sino-Japanese Conflict.” This clause was, of course, directed against the United States. Article 4 of the Treaty made the first formal provision for military, naval and economic collaboration. It declared: “With a view to implementing the present Pact, Joint Technical Commissions the members of which are to be appointed by the respective Governments of Japan, Germany, and Italy will meet without delay.”

During 1941 Germany exerted every effort to induce Japan to enter the war against the British Empire. Foreign Minister von Rib- bentrop repeatedly pointed out to General Oshima, Japan’s Ambassador in Berlin, the alleged advantages of such action, declaring that Great Britain would soon collapse before German might in Europe, and that the way was open for Japan to advance into Singapore, assuring the success of the “New Order in Greater East Asia.” In March, 1941, the Japanese Foreign Minister, Matsuoka, a leader among the extremists in Tokyo, visited the German capital, and again the Nazis argued that Japan had everything to gain by attacking the British in the Far East, claiming that Germany already was winning the war.

Plans for Collaboration, 1941

At the time of the Matsuoka visit, the question of collaboration in naval and military fields received some consideration. On March 5, 1941, the German Armed Forces High Command issued Basic Order Number 24 regarding collaboration with Japan. According to this document, which was classified top secret and circulated only to the highest military and government authorities, Hitler issued the following orders:

(1) It must be the aim of the collaboration based on the Three Power Pact to induce Japan as soon as possible to take active measures in the Far East. Strong British forces will thereby be tied down, and the center of gravity of the interests of the United States of America will be diverted to the Pacific. The sooner it intervenes, the greater will be the prospects of success for Japan in view of the still undeveloped preparedness for war on the part of its adversaries.. . .

(2) To prepare the way for collaboration it is essential to strengthen the Japanese military potential with all the means available. For this purpose the High Command of the branches of the Armed Forces will comply in a comprehensive and generous manner with Japanese desires for information regarding German war and combat experience and for assistance in military economics and in technical matters. Reciprocity is desirable but this factor should not stand in the way of negotiations. Priority should naturally be given to those Japanese requests which would have the most immediate application in waging war.

In special cases the Fuehrer reserves the decisions to himself.

(3) The harmonizing of the operational plans of the two parties is the responsibility of the Navy High Command.

This will be subject to the following guiding principles:

(a) The common aim of the conduct of war is to be stressed as forcing England to the ground quickly and thereby keeping the United States out of the war. Beyond this Germany has no political, military, or economic interests in the Far East which would give occasion for any reservations with regard to Japanese intentions.

(b) The great successes achieved by Germany in mercantile warfare make it appear particularly suitable to employ strong Japanese forces for the same purpose. In this connection every opportunity to support German mercantile warfare must be exploited.

(c) The raw material situation of the pact powers demands that Japan should acquire possession of those territories which it needs for the continuation of the war, especially if the United States intervenes. Rubber shipments must be carried out even after the entry of Japan into the war, since they are of vital importance to Germany.

(d) The seizure of Singapore as the key British position in the Far East would mean a decisive success for the entire conduct of war of the Three Powers.

In addition, attacks on other systems of bases of British naval power—extended to those of American naval power only if the entry of the United States into the war cannot be prevented— will result in weakening the enemy’s system of power in that region and also, just like the attack on sea communications, in tying down substantial forces of all kinds (Australia).

A date for the beginning of operational discussions cannot yet be fixed.

(4) In the military commissions to be formed in accordance with the Three Power Pact, only such questions are to be dealt with as equally concern the three participating powers. These will include primarily the problems of economic warfare.

This order was signed by Keitel, Chief of the Armed Forces High Command.

The last paragraph of this order indicates that the joint commissions envisaged by the Three Power Treaty of September, 1940, had not yet been established at the time of the Matsuoka trip to Berlin six months later. Actually very little cooperation in naval and military matters had been undertaken following negotiation of the Treaty. In October it was reported that a group of German naval experts had been sent to Japan to assist in the construction of air and naval fuel bases, but nothing of any greater consequence appears in the records.

During his Berlin visit Matsuoka raised the question of German assistance in the event of a Japanese attack upon Singapore, to which von Ribbentrop replied that he had already requested the Japanese ambassador to supply maps of the Singapore area so that Hitler “—who probably must be considered the greatest expert on military questions at the present time (sic!)—” could advise the Japanese on the best method of attack. In a conversation with Hitler, Matsuoka repeated the request for assistance. He indicated that the Japanese armed forces could handle the offensive against Singapore, but that this operation entailed the risk that the United States would enter the conflict on the side of the British. “Japan would do her utmost to avoid a war with the United States,” Matsuoka declared to Hitler. But “the Japanese navy . . . had to be prepared for a fight with the United States.” He expressed his personal belief that the United States could be restrained by diplomatic exertions from entering the war on the side of Great Britain. The Japanese army and navy, however, had to count on the worst situation, that is, war against America. They were, he declared, of the opinion that a Japanese- American war would extend for five years or longer and would take the form of guerilla warfare in the South Pacific. For this reason, German experiences in her submarine warfare were of the greatest value to Japan. It was a question how such a war would best be conducted and how all the technical improvements of submarines, in all details such as periscopes and such like, could be exploited by Japan. The Japanese Foreign Minister requested Hitler to see to it that the proper German authorities make available to the Japanese such developments and inventions as were required. Again he declared that knowledge of the latest improvements was needed, “because the Japanese navy had to prepare immediately for a conflict with the United States.”

Hitler, following the policy set forth in the Basic Order Number 24 cited above, promised to carry out this request. He pointed out that Germany likewise considered war between Japan and the United States undesirable, but that his government had already made allowances for such a contingency. He assured Matsuoka that Germany would come into the war against the United States as a result of action in the Far East.

In spite of this exchange of views between Matsuoka and Hitler, very few steps were taken toward cooperation between the Axis members in naval and military matters, nor were realistic plans made for the future. In the spring of 1941 Japanese naval and military inspecting groups were dispatched to Germany and Italy. The groups visited manufacturing plants, airfields, naval vessels, and fortresses in Germany, Italy, and France (at that time occupied by Germany). The chief of the Japanese naval group, a vice admiral, remained in Berlin as head of the Japanese Naval Affairs Commission established under Article 4 of the Three Power Treaty, and a similar Japanese commission was created in Rome. These commissions acted as liaison groups with the German and Italian Navy ministries and other appropriate agencies. Germany and Italy did not send inspecting groups to Japan, although their naval and military attaches in Tokyo visited various Japanese installations. Nor did Germany and Italy establish special naval commissions in Tokyo. Rather they continued to act through their regular attaches in the Japanese capital. Apparently the Japanese attached greater importance to these arrangements than did the other Axis powers. Vice Admiral Nomura, who served as naval commissioner in Berlin, testified after the war that up to this time contacts with the Germans had been limited because of German insistence upon pomp and ceremony. For this reason, he declared, the Japanese navy dispatched officers of high rank who were able to meet with the top German authorities.

The records indicate that neither the Japanese nor German navies considered mutual cooperation at this time a matter of much significance in their over-all war plans. The only contrary evidence relates to the attempts of the Japanese to secure technical information. It was seen above that this matter was carried to the highest level when Foreign Minister Matsuoka made a direct request to Hitler for such information. During 1941 the Japanese appear to have attached increasing importance to their attempts to secure information on German naval techniques. It will be recalled that by this time the United States government had extended embargoes on exports to Japan, and finally in mid-summer had virtually terminated all trade relations. Admiral Nomura, the Japanese naval commissioner in Berlin, pointed out that prior to the breakdown of trade between America and Japan, the Japanese navy tried to learn American mechanical methods by importing American products, but when the embargoes were tightened Germany became the only country upon which Japan could depend. Consequently the Japanese navy sought to increase its knowledge of German techniques. It is doubtful if the Japanese obtained information of much value at this time, however. The same Japanese admiral stated that when his mission called upon Admiral Raeder, chief of the German navy, requesting information and advice, Raeder put him off with the reply that since the Japanese navy was superior to that of Germany, it was for the Germans to study Japanese developments.

Thus on the eve of the attack upon Pearl Harbor, which was to launch Germany and Italy as well as Japan into war against the United States and its allies, little effective effort had been directed toward planning for naval or military collaboration among the Axis partners. The reasons for this situation stemmed directly from the nature of the Axis alliance itself. In the first place, Germany and Japan entered upon this alliance entirely with opportunistic motives. This was a political arrangement, negotiated without reference to naval or military considerations. Neither the leaders of Germany nor of Japan thought in terms of rendering direct assistance to the other party, or of joining together in combined operations against the common enemies. Germany, determined to conquer all of Europe and adjacent areas, wanted to get Japan into the war as a means of further weakening Great Britain (and subsequently the Soviet Union), and of diverting American attention to the Pacific. Germany did not have immediate ambitions in the Far East, so had nothing to lose by drawing Japan into the conflict. She hoped, moreover, that Japanese conquest of British and Dutch territories in the Far East would open up supplies of rubber and other raw materials, at that time denied to her. Japan likewise had no ambitions in Europe and did not expect to participate in the war in that area, but she did wish to take advantage of Britain’s plight to satisfy her own designs in the Far East. As Ambassador Grew pointed out, the Three Power Treaty was “a tremendous Japanese gamble on the defeat of Britain by Germany.” It also was a gamble by both Japan and Germany that the declaration of an Axis alliance would keep the United States out of the war; or that if America were to enter the war, her delay in preparation would enable each of the Axis partners to secure victory in its own sphere before America’s industrial potential might be brought to bear in the conflict.

Another factor which perhaps contributed to failure to implement the Axis alliance beyond the political level was the fact that it was the product of scheming among the Nazi conspirators and their Japanese counterparts, the Hitlers, von Ribbentrops, Matsuokas, and Oshimas, and that responsible naval personnel had no part in its formation. Naval circles in Japan, moreover, clearly opposed the association with Germany, while in Germany the navy occupied a minor role in relation to the Nazi party, the army, and the Luftwaffe.

From this review of the mutual relations of Japan and Germany as they developed through the year 1941, it is seen that neither party considered the Axis partnership as anything more than an alliance of convenience, and that neither contemplated close collaboration with the other. This situation was best demonstrated when Germany made war upon the Soviet Union and Japan attacked Pearl Harbor without prior notification to the other party.

Wartime Collaboration, 1941-1945

After the United States became a full- fledged belligerent against the Axis, there was no alteration in the political conditions which limited the scope of Japanese-German collaboration. The principal obstacle to combined or coordinated operations was the inability of the governments of the two powers to maintain direct consultation. Certainly the success of Allied collaboration was in large measure the outcome of the personal contact established between the chiefs of state and general staffs of the United States and the United Kingdom and subsequently of the Soviet Union at Casablanca, Quebec, Teheran, and Yalta. It was impossible for the high authorities of Japan and Germany to hold similar meetings, and such contact as was maintained was limited to the activities of liaison officers. Under these circumstances there was no real chance of coordinating the war plans of the two powers, and such collaborative ventures as were attempted were subject to restriction or change by either party in the light of its own independent operations.

Japan and Germany thus very largely fought their own wars and joined forces to a minor degree. Shortly after the Pearl Harbor attack, however, arrangements were made for closer cooperation than had been planned under the Three Power Treaty. Had the circumstances of the war favored the Axis, this cooperation probably would have increased in extent and effectiveness. On January 19, 1942, Japan, Germany, and Italy concluded a Three Power Military Agreement which provided the basis for collaboration in operational matters for the rest of the war. The agreement was drawn up in general terms and was signed by the German and Italian Chiefs of Staff and representatives of the Japanese Chiefs of Staff. The details of collaboration were handled through the Japanese naval commissioners and their aides resident in Berlin and Rome and the German and Italian attaches in Tokyo. Besides the ordinary channels of communication, a special naval communications system was established between the three countries. Plans were formulated in the early stage of the war for air communication, but only one Italian plane made the complete trip to Japan. A Japanese plane attempting a flight to Europe was lost over the Indian Ocean, and the Germans abandoned their plans for a flight.

Perhaps the most ambitious plan for Japanese-German naval collaboration was for submarine warfare against merchant shipping in the Indian Ocean. This plan appears to have been largely German in inspiration and initiative, and was envisaged in the German Order Number 24 of March, 1941. It was the only undertaking, naval, military or air, in which the Axis actually was able to carry out combined operations of any significance. These operations continued from 1942 until about July, 1944. According to the military agreement, the Japanese operated east of 70 degrees east longitude and the Germans to the west. As the war progressed, however, the dividing line was removed and it was agreed that the vessels of each navy could operate in any area.

The extent to which the two navies succeeded in following a coordinated plan of operations in the Indian Ocean is not altogether clear. Apparently the Germans acted with a good deal of independence. Vice Admiral Miwa, commander-in-chief of the Japanese Sixth (submarine) Fleet, testified after the war that he did not have communication with the Germans, nor did he have any control over their operations. Such coordination as did exist was worked out through the liaison groups in Berlin and Tokyo. The officers of a few Japanese and German submarines did meet on each other’s boats and exchange views. The Germans, moreover, established additional liaison groups for their submarine operations at Singapore and Penang, and at one time planned a supply base and rest center at Singapore. When the British mined the Malacca Strait and increased their submarine defenses in that region, the German operational base was removed to Batavia. The Japanese supplied two naval seaplanes which were flown by German crews and used to protect German submarines moving through the Sunda Strait.

The potential effectiveness of Axis submarine warfare in the Indian Ocean was limited by a difference of opinion between the Japanese and Germans concerning the employment of submarines, a difference which never was resolved. The German Navy Ministry was particularly anxious to induce the Japanese to exert their maximum effort against Allied merchant shipping. This ran counter to the Japanese naval doctrine that the fundamental mission of submarines was to serve as auxiliaries to the fleet. During 1942, however, the Japanese were persuaded to divert some of their submarines to the Indian Ocean and the waters around Australia for the purpose of destroying merchant vessels. This action was contrary to the wishes of the commander-in-chief of the Japanese submarine forces.

As the war continued and Japanese naval losses in the Pacific mounted, Japanese authorities reverted to their established practice of reserving their submarines for action against enemy naval forces, and subsequently they were obliged to use their undersea craft to supply isolated island outposts. The Germans continued to urge the Japanese to attack merchant shipping, particularly tankers and transports between Honolulu and the West Coast. The German naval attaché in Tokyo has testified that this matter was a subject of repeated exchanges between Berlin and his office, and that his directives instructed him to press the Japanese further. But the Japanese invariably gave the same answer, that they must conserve their submarines for attack against the United States fleet. They argued that merchant shipping could be easily replaced because of the great American productive capacity, but that naval vessels, particularly carriers, and their trained crews were most difficult to replace and hence were the logical targets.

The Japanese did, however, recognize German superiority in submarine warfare, and they were eager to learn German techniques. It will be recalled that this matter had been discussed by Foreign Minister Matsuoka in his conversations with Hitler in March, 1941. The German navy arranged to sail two 740-ton type submarines to Japan. One appears to have been lost en route, but the second got through to the Kure Naval Yard in September, 1943. The Japanese studied it carefully, removing its equipment and looking into its construction. The submarine was accompanied by technicians, who instructed the Japanese in German methods. But according to the German naval attaché, the Japanese concluded that this type of boat was too complicated for construction in Japan at the time. The Japanese contemplated sending a submarine in return as a gift to the German navy, but the plan never materialized. One full Japanese submarine crew was sent to Germany for training in German boats and attack methods, but it was lost at sea in the attempt to return to Japan early in 1944. Toward the end of the war more elaborate plans were worked out for exchange of technical information and personnel for the construction of aircraft, high speed submarines, anti-tank weapons, and so forth; but due to the complete breakdown in sea transportation, nothing could be done.

With the mounting success of American submarine activity in the Pacific, the Japanese sought to improve counter devices, including radar and an underwater breather. They worked independently on these devices, but also turned to the German navy for technical assistance. The commander-in-chief of the Japanese submarine fleet testified that they secured considerable information from the Germans relating to defense against radar detection.

In the spring of 1945, just prior to the German collapse, the Japanese navy requested that a large number of German submarines be sent to Asiatic waters before surrender, but the request was rejected—in part because of the fuel shortage and the dangers of escaping through the Atlantic.

During the summer of 1943, under different circumstances, the Japanese navy succeeded in defeating a plan which would have called for the transfer of major naval units to the Singapore region. Vice Admiral Fukudome, who was at the time the chief of staff of the Combined Fleet, has testified that the central authorities in Tokyo were of the opinion that the greatest threat to Japanese defenses would be from the west, across the Indian Ocean, rather than from the east across the Pacific. This was following the Allied conquest of North Africa and the collapse of Italy. According to his testimony, the central authorities believed that the American and British fleets would attack across the Indian Ocean in support of Allied landings in Malaya. Admiral Koga, Japanese commander-in-chief, strongly rejected these calculations, however, insisting that the major threat was from the United States fleet across the Pacific, and that Japanese strength should not be weakened by shifting vessels to Singapore. The central authorities finally agreed with Koga. It was decided that the navy would not be responsible for the defense of Malaya. It is not likely that the Germans figured in these considerations.

On one occasion a German raider, a converted passenger liner, operated in the Pacific. She sailed from the Indian Ocean westward around the Cape of Good Hope, across the South Atlantic, and on around Cape Horn into the Pacific, heading for Kobe. But she was torpedoed in September, 1943, off one of the Bonin islands, where she had put in to refuel. According to the German naval attaché in Tokyo, the submarine surfaced after sinking the ship and picked up two German prisoners. These prisoners were not heard from again, and he suggested that the German raider may have been sunk by a Japanese submarine.

It will be recalled that the German High Command in its Order Number 24 of March, 1941, relating to collaboration with Japan, had indicated a hope that Japanese conquest of Indonesia would open up supplies of raw materials to Germany. Sometime after Pearl Harbor the Axis partners concluded a Three Power Economic Pact relating to the exchange of goods and materials, and including such details as reciprocal use of patent rights and military weapons. The inability of the Axis to gain control of sea communications made it impossible to realize these ambitions. Attempts were made, however, to run the Allied blockade between Germany and Japan. During 1942 a few German cargo vessels, converted as armed cruisers, endeavored to get through from French ports, but the effectiveness of Allied submarine activity, particularly in the Atlantic and between Japan and Singapore, forced the discontinuance of this scheme. Subsequently the plan to use submarines as cargo carriers was devised, and ten German and five Japanese boats were assigned for the purpose. Again Allied counter measures proved to be effective, and many of the Axis submarines were lost. Only five German and three Japanese boats succeeded in making the run.¹ They operated between Penang or Singapore and French Atlantic ports, transporting small quantities of rubber, tin, quinine, and other vital raw materials, and returning with optical goods, machine tools, small arms, plans for aircraft, and samples. The submarines were employed also for the exchange of technical personnel.

Conclusion

In conclusion, it can be seen that collaboration between the Japanese and German navies did not amount to much. German hopes to induce the Japanese navy to help in the destruction of Allied shipping met with only temporary and minor success, nor was Germany able to take advantage of Japanese conquest of Indonesia to secure much needed rubber and other vital raw materials. Japan, for her part, was able to secure some technical assistance from her Axis ally, but this assistance was minor when compared to her needs. Thus Japanese-German collaboration was a far cry from the threat of an Axis junction in the Indian Ocean or Middle East pictured by some alarmists in 1942. But the situation might ultimately have been far different had it not been for the Allied victories, starting at Midway, which turned the tide against the Axis and led to the final surrender at Tokyo.