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Mr. Merrill is a member of the League with a long and distinguished association with the Submarine Force. He is a retired engineer from the New London Division of the Naval Undersea Warfare Center and has been a frequent contributor to this magazine.


When World War I broke out in Europe on August 4, 1914, Great Britain declared war against Germany. At first, the British assumed that Japan would remain neutral. However, several days later, Great Britain asked Japan for naval assistance against the Imperial German Fleet in the Pacific. Participation by Japan would be in compliance with a provision of the then current Anglo-Japanese Alliance. Two weeks after the start of the World War, on August 24, 1914, Japan’s naval support of Great Britain began in the Pacific Ocean with a Japanese declaration of war against Germany.

The roots for Great Britain’s request were established in a highly secret nine months period of negotiations in 1901-02 between these island maritime nations. The new Anglo-Japanese Alliance was officially accomplished January 30, 1902 with a public announcement in February. Prior to promulgation, the Alliance was shown to Washington (a silent partner). An Alliance benefit was that it would help maintain an open door to the Orient.

One part of Japan’s initial participation involved an almost immediate successful joint sea and land attack with Great Britain against the important German Yell ow Sea port and naval base on leased land at Tsingtao on the Shantung Peninsula. The action ended on November 7, 1914. Other elements of Japan’s naval advocacy during the following four years included assistance in the Pacific and Indian oceans. It is a bit surprising that in 1917-18, Japanese destroyers fought German and Austro-Hungarian submarines in the Mediterranean. Japan’s support for the Allies came in other ways as well. In 1916, Japan delivered thirty-four trawlers to France. The following year, in five months 2 Japanese shipyards built 12 Kaba class destroyers for France. This is the first example of a European power using Japanese industry on a large scale.

Why did Great Britain enter into an Alliance with Japan?

This diplomatic move was a first in several respects. It was the first full-scale alliance with any nation by Great Britain in almost a century. In the new century, Great Britain found itself in financial straits as a result of the on going twenty-seven month war (1899-1902) with the Boers in South Africa and in the beginnings of a naval race with France and Germany. The primary naval powers placed emphasis on costly and manpower intensive capital ships (dreadnoughts). This focus placed a limit on the availability of cruisers and other naval ships that proved to be better suited to the type of naval warfare that evolved in thel914-18 war.

According to naval historian Arthur J. Marder,” … from 1901-02 Admiralty looked upon Germany as the potential enemy of the Royal Navy. “Further, France and particularly Russia were presumed to have designs on parts of the Far East critical to Great Britain’s interests (northern India and China). A global British Empire and a sometimes-extended Royal Navy could use support from a country with a proficient navy and strong maritime interests.

The Japanese success in the Sino-Japanese War (1894-95), that was fought over supremacy in Korea, was a sound defeat for China on land and sea. Japan emerged as a major world power and gained Taiwan, and treaty rights in Manchuria and Korea. Gaining as an economic power, Japan looked for assurance in holding the gains made of that war. An alliance with Great Britain offered advantages.

A further alignment in diplomatic arrangements was the 1904 agreement between England and France that resolved their antagonisms and controversies but was not an alliance.

The initial Anglo-Japanese Alliance allowed that in the event of Japan at war with Russia, Great Britain would remain neutral. Great Britain would intervene if a second power came to Russia’s aid. Containment of Russian power and maintaining an “open door” policy for China trade were principal goals. The Russo-Japanese war followed shortly after the signing of the Alliance. The war required Russia to move a substantial part of its coal-burning fleet 20,000 miles from the Baltic to the northern Pacific Ocean. The Alliance partnership precluded Russian ships from coaling ashore on the voyage from the Baltic.

The Alliance was renewed, on August 12, 1905, just prior to Japan’s victory over Russia and the signing of the peace at Portsmouth, New Hampshire. The Alliance deliberations at the renewal included participation by the Alliance partners in the event of a single power attack on one of the partners. Further, there was acknowledgement of Japan’s interest in Korea. Discussion by the Alliance partners included consideration of appropriate action in the event of a probe by Russia into northwest India. By 1907, France, Russia, Japan and Great Britain shared common goals. In 1910, there was British support for Japan’s goals in Manchuria. The same year Korea became a Japanese colony.

On July 13, 1911, the third Alliance treaty was signed in London. It renewed and extended the Alliance. At this point, the needs of the participants were divergent on some issues. One of Great Britain’s foremost interests pertained to the security of the Pacific Ocean area dominions of Australia and New Zealand. There were policy differences regarding China. Japan looked for protection against the fear of isolation in the Pacific vis-a-vis the United States. This version of the alliance-excluded America from the nations that Britain would fight on Japan’s side and provided a basis for Japan’s eventual war declaration three years later.

At a May 1911 British ministerial meeting in London prior to the ten-year Alliance extension with Japan, a hypothetical case of a discontinuance of the Alliance with Japan in 1914 was considered. Foreign Secretary Sir Edward Grey presented the following statement: ….. in the interest of strategy, in the interest of naval expenditure, and in the interests of stability, it is essential that the Japanese Alliance be extended.”* It appears prescient that the year 1914 was provided as an example.

Japan’s disposition regarding the four-year war with Germany is clouded. At various points during the War, there seems to have been a reluctant willingness to participate. When participation did occur, it was effective and did help the Allied cause.

In the years leading up to the war, diplomacy and treaty building were not the singular concern of nations with substantial navies. It was a period of rapidly changing and improving technology of the fighting ships including their construction, capability and weaponry. Further, advancement in the development, manufacture, and improvements in naval guns, mines, depth charges, submarines, and torpedoes provided additional challenges to the countries’ naval tacticians and naval strategists. Technological advancements brought increased skill requirements for the men manning the ships and as previously mentioned, fiscal limitations were omnipresent. Many challenges were to be encountered and at the same time occasions occurred for errors to be made. It is pertinent to mention that the primarily coal-burning naval warships were a huge encumbrance for the navy planners, strategists, and tacticians at all times.

Pre-war British Naval Position

Great Britain concentrated its fleet in home waters, not for home islands protection but to prevent German cruisers from breaking out into the oceans and trade routes. This period also saw a reduction in the Royal Navy’s Mediterranean and China squadrons and termination of the South Atlantic force. As early as 1905, the Admiralty slowly moved toward a policy of recalling the Mediterranean fleet in time of war, first under some contingencies and then under most.’ Fiscal and naval manpower considerations helped foster the reductions. Man-power for the growing navies of the competing powers of Great Britain and Germany was also a priority. It happened that England maintained its navy with volunteers while Germany used conscription to fulfil its quotas. As mentioned above, the manpower sought now had an additional need: competence in technological areas.

Under these conditions, naval support for Great Britain around the globe came from good relations with the United States providing a naval backup in the western Atlantic as well as in the Pacific. France provided important naval coverage in the Mediterranean with the 1904 Entente mentioned above.

Japan Enters the War

Japan quickly accepted the naval role of protecting Britain’s interests in the Pacific as the War started. Initially, Japan’s viewpoint made it clear that the ground war was a European event and not in the sphere of interest for the Japanese Army. However, by February of 1916 a willingness to send troops to the West was stated. In some instances the expression willing reluctance may have been appropriate. The record shows that in addition to naval support for the Allied cause Japanese support included arms, industrial products, shipyards, and merchant ships.

“On August 15, Japan, acting with the advice and consent of Great Britain, sent an ultimatum to Germany demanding the immediate withdrawal of German warships from the Orient and surrender to Japan of the leased territory of Kiauchau (Shantung Peninsula ). 10 With no response from Germany, Japan declared war on August 23. The remainder of the year saw Japanese naval action mainly in two different areas. One was (as previously mentioned) the immediate joint action with components of the British Navy in the siege at Tsingtao on the Yellow Sea. The other direct action was to take Germany’s Pacific Micronesia islands. Before the end of the year both were successful.

Germany in the Pacific

Germany was well established on China’s Shantung Peninsula. Sino-German commercial collaboration on the Shantung Peninsula and German acquisition for99 years of Kiauchau, a 200-square mile area, dated from 1897. In the following years, Tsingtao, Germany’s only fortified base in foreign waters, included a German-style city, industrial and maritime facilities, and substantial fortifications on the bay.

By 1914, German holdings in the Pacific also included the Mariana, Marshall, Caroline, New Guinea, Samoa, and Solomon Islands distributed on both sides of the equator and mostly west of the 170′ longitude line.

At the time of Japan’s declaration of war against Germany, the Shantung German industrial and military garrisoning was significant. Total troops numbered about 6,000, and naval support included an Austro-Hungarian armed cruiser, five gunboats and two destroyers.

Germany’s East Asiatic Squadron under the leadership of Vice Admiral Maximilian Graf von Spee, equipped with the new armored cruisers Schamlwrst and Gneisenau plus three light cruisers, was the challenge to the British in the Pacific. Normally based in Tsingtao, von Spee in a pre-war move by July 17 removed his armored cruisers from the Shantung region to the Caroline Islands. The Admiral’s plan was to impact British trade routes by operating off the West Coast of South America with coaling capability at Chilean ports. Intelligence regarding the location of naval vessels of both sides in remote oceanic areas was frequently incorrect or not available.

Japan’s late August entry in the war with a clear naval superiority in the Pacific motivated Admiral von Spee’s disposition of his forces. This is exemplified in the light cruiser Emden ‘s November 9 assignment to the Indian Ocean. After three months of successful encounters, the Emden was sunk off the Cocos Islands in the Indian Ocean by the Australian light cruiser Sydney. The Emden ‘s successes during that period included sinking or capturing seventeen British merchant ships of 68,000 tons in the North Pacific and Indian Oceans. During these early months of the war, Germany’s East Asiatic Squadron was gradually decimated.

In addition to sinking and capturing ships of British registry, two significant open sea battles occurred in the next several months. These battles have been noted as the last open sea battles of the 20th Century fought without sea mines, submarines and airplanes. The first was the clash between mostly light and heavy German and British cruisers off Coronel on the coast of Chile on November l, 1914. This was a decided victory for the Germans. Two of the four participating British men-of-war were lost with no German ship losses. This was the first naval battle loss by the British in one hundred years.

On December 8, a second sea battle of armed cruisers occurred in the South Atlantic at the Falkland Islands with the Dresden escaping and the other six German ships sunk. Von Spee was lost with his flagship-armored cruiser Scharnhorst. His two sons were also lost in the battle. Even with a much-reduced German cruiser capability in the Pacific and Indian Oceans, there was a contributing naval role for Japan throughout the war.


Prior to an August 23 declaration of war against Germany and with China in a neutral status, Japan with a strong interest in the German holdings on the Shantung Peninsula, immediately authorized a blockade of Tsingtao. The New York Times on August 17, 1914 headlined the beginnings of the assault with 16,000 Japanese troops embarking for the Yell ow Sea stronghold and included a map of the area. The following three-month siege of the long-held and well-established German stronghold ended with the German surrender on November 7. Land and sea forces were primarily Japanese. Other Western Allied participation was minimal with British naval support and troops, South Wales Borderers and the 36th Sikhs from the Tientsin Hong Kong Garrison.

Twelve forts and barracks for 5000 troops protected Tsingtao and environs. It was considered the Kaiser’s stronghold in the Far East and sometimes identified as the “German Gibraltar of the East.” 11 At the time of the Japanese assault, several thousand additional support troops were added. The Japanese naval assault and landings with 60,000 troops, including British participation, began in early September. The extensive bombardment included both land and naval encounters. A German- Austro-Hungarian surrender occurred November.

Wakamiya Sea Plane Tender

A Japanese trading ship, Wakamiya, modified as a seaplane tender and equipped with 4 Farman tloatplanes, entered service in 1913. During September at Tsingtao, Wakamiya’s seaplanes (with a speed of 60 mph and ceiling of 1500 feet) participated in a great number of sorties, dropped bombs, and provided observations. Pilots used visual communications with each other. Even with the limitations of the aircraft involved at that time, the value of aerial observation at sea and other capabilities of planes in naval warfare did not go unnoticed.

German Pacific Islands

Historians, considering Japan’s objectives as an ally, identify taking possession of the German holding in China’s Shantung region and the various German Micronesian islands as a primary goal. The successful siege of Tsingtao was consummated with the German surrender on November 7, 1914. Almost immediately (January 18, 1915) Japan submitted 21 demands to China regarding Japanese claims. The Sino-Japanese treaty of May 25, 1915, allowed Japan rights in southern Manchuria, eastern Inner Mongolia and Germany’s economic holdings on the Shantung Peninsula.

Even more quickly within two weeks of declaring war against Germany, German colonial possessions north of the equator in the Pacific surrendered to Japan. The Marianas, Caroline Islands (East), Caroline Islands (West), and the Marshall Islands were captured and occupied by the Japanese on about October 6, 1914. Resolution of Japanese long-term entitlement to these islands and clarification of eventually returning the Shantung region to China were resolved at the 1919 Peace Conference.

Japanese Naval Role 1915-1916

Immediate opportunities for Japanese naval support included assisting in the search for Germany’s remaining battle cruisers in the Pacific and Indian Oceans. Japan also provided convoy assistance to the vast movement of Australian and New Zealand troops and war materials across the Indian Ocean. With a reduced British naval presence, especially in the north Pacific, as well as a lessening of German capability, Japan’s naval presence became significant. Japan’s occupation of the northern German Micronesian islands also caused concern and discomfiture with the British dominions of Australia and New Zealand. This concern presented it self later at the peace negotiations in France.

Singapore Indian Troop Mutiny 1915

January and February of 1915 saw unrest within the Indian Army in India and abroad. Planned army uprisings in January 1915 at Rangoon, Burma and February at Lahore, India were aborted. At Singapore February 15, the 5 1h Light Infantry Battalion of 800 (all Punjabi Muslims), plus I 00 members of the Malay States Guides Mule Battery mutinied.

On Singapore Island, there were 231 regular European troops. Thirty-two British soldiers and civilians were killed. German prisoners were released, a few fled. Within ten days the insurrection was subdued, the support coming from marines and crews from British, French, Russian and Japanese warships in port. Several hundred civilians also were involved in the suppression of the mutiny. On February 17, two protected Japanese cruisers Tsushima and Otowalanded marines in the action. It has been mentioned that about 100 Japanese marines and sailors came ashore to assist.

Mediterranean Submarine Warfare 1917-18

By the middle of April 1917, the adversaries within the confines of the Mediterranean in the anti-submarine war included Great Britain, Italy and France aligned against Germany and Austria-Hungry. Italy, neutral since August 3, 1914 gave up its neutral status and declared war against Austria-Hungry in 1915 and Germany in August 1916.

Germany’s late 1916 reinstitution of unrestricted submarine warfare proved to be highly successful as the new-year opened. With a total of 150 U-boats engaged in unrestricted warfare, the February and March 1917 total overall tonnage lost to the U-boats was on track for an Allied disaster by fall of that year. Further, the exchange ratio of the number of Allied ships sunk to the number of submarines lost reached 167 per U-boat by April, a five fold increase from the February exchange ratio of 53 per U-boat. Overall, 25 % of the total British shipping loss during the War from mines and submarines occurred in the Mediterranean. Seven percent of the total sinkings of the War took place in April 1917.

In spite of historical evidence favorable to convoying ships, the Allies in World War I waited nearly three years until April 1917 to invoke convoy as a way to effectively curb the very successful U-boat sinking of merchant ships. It was under these near-crisis loses from the U-boats that Great Britain requested Japan’s naval support in the Mediterranean. More than one request was required to have a Japanese naval presence in the European Theater. Japan sunnised that sending a fleet would leave the Pacific open to expansion of American naval power.

The United States as a recent entrant into the war did not have a presence in the Mediterranean until 1918. By then, with the war winding down, there were thirty-six United States newly constructed 110-foot wooden submarine chasers operating out of Corfu and an additional 18 assigned at Gibraltar.

Japanese Naval Presence in the Mediterranean 1917-18

On February 16, 1917, Great Britain advised Japan that in a post war environment, it would agree to Japan’s claims to German rights in Shantung and possessions in the islands, of the Marshall, Caroline and Marianas Archipelagos, north of the equator. Australian rights to the German areas south of the equator were part of the agreement. This secret agreement also had assurance from the Russian, French, and Italian governments. Perhaps this agreement ended Japan’s slow and reluctant response to Great Britain’s request for help in the Mediterranean. At the 1919 Peace Conference at Versailles, this concession was granted with the exception that the date and conditions for the return of the Shantung area to China was not specified.

Mid-April 1917, a Japanese Mediterranean squadron of destroyers began to assemble at Malta to assist the Allied fighting against the German and Austro-Hungarian U-boats. The Japanese destroyers, initially 12, with cruiser flagships were an important part of the anti-submarine convoy escort.” Destroyers were needed to hunt submarines or provide escort for the now heavily invoked convoy system. Marder’ s comment regarding destroyer performance in the Mediterranean points out the efficiency of the dozen Japanese destroyers.

Destrovers:Time at sea

Japan British French/Italian
72% 60% -45%

In June 1917, in recognition of the Japanese ship handling skills, the British transferred to Japan for duration the Acom (H) class destroyers HMS Nemesis (Kanran) and HMS Minstrel (Se11da11). The ships were returned in 1919. This brought the number of Japanese destroyers in the Mediterranean to fourteen. Marder in From the Dreadnaught to Scapa Flow points out the seriousness of some of Japan’s destroyer captains, “So impregnated with a sense of duty that some of their destroyer captains committed hara-kiri when a U-boat sank a ship they were escorting!”

May 3, 1917

On this date, the British troopship Transylvania, an ex-Cunard ship, departed Marseilles bound for Alexandria with about 200 officers and 2,860 troops. The Japanese destroyers Matsu and Sakaki escorted the ship. On the following day in the Gulf of Genoa, the German submarine U-63 torpedoed the Transylvania.

During passenger offloading to the Matsu, the Sakaki attempted to force the U-boat to remain submerged. A second torpedo from the U-63 caused the Transylvania to sink more rapidly. One of the destroyers saved 1,000 of the survivors. Other vessels came to assistance, but most of the survivors were aboard the Japanese ships. In all, 414 passengers lost their lives. 19 Later the New York Times reported that during the rescue effort, a second torpedo struck and “blew the ship sky high.”

June 11, 1917

“Japanese Destroyer Damaged, while Japanese destroyers were attacking a submarine in the Mediterranean on June 11, the destroyer Sakaki was torpedoed and damaged, says an official announcement of the Japanese Admiralty June 15. The damaged craft was towed to port. The Japanese Naval attache in London announced the loss of 55 lives aboard the Sakaki. – N.Y. Herald, 17,6.”

Other references identify the source of the torpedoing that destroyed the bow of the Sakaki with a loss of 68 of the 92-person crew as the German designed Austrian submarine U-27. The destroyer was on escort duty off Crete in the eastern Mediterranean. The destroyer was salvaged and repaired. Shortly after this incident the U-27, a 121-foot submarine with a crew of30 at sea for 90 days, traveled 4200 miles on the surface and 70 miles submerged in the eastern Mediterranean and evaded, attacked, and sank a number of ships.

To help place the scale of Japanese participation in perspective, by early 191 7 Allied vessels against submarines in the Mediterranean included 147 destroyers, 75 torpedo boats, 200 trawlers, 68 submarines, 78 sloops, gunboats and other craft.

Halpern in Naval War in the Mediterranean ( 1987) noted Japanese destroyer support: ‘The Japanese were largely responsible for escorting troopships, in fact the postwar study by the Mediterranean Staff concluded that without the assistance of the Japanese forces ‘the situation would have been impossible.”

United States and Japan Relationship

Japan’s naval role of assisting Great Britain was extended to the United States with President Wilson’s declaration of war in April of 1917. Throughout the war an attitude of suspicion towards Japan and its goals was held by some in United States and Great Britain. With exceptions, an air of diffidence seems to have been detected in many quarters of the governments when dealing with Japan. The incident of the Zimmerman Telegram and the United States policy regarding immigration of Japanese during the remaining years of the war provided a source of continuing diplomatic difficulties.

One of the immediate benefits from Japanese naval coverage in the Pacific was that it allowed the United States to move naval forces from the Pacific to directly aid the British. The agreement between the American and Japanese government made it possible for the United States to withdraw ships from the Philippines and from the Western Pacific as those waters were protected by Japanese vessels. The Japanese warships patrolled the Pacific Ocean from Japan to Manila, then to Honolulu, and as far south as the South Sea Islands.


In the final years of the War, Japan was requested to provide more naval assistance in the European Theater. The response mentioned that Japan was already in the Pacific Ocean, Indian Ocean, Australian waters, the Mediterranean, and in 1918 in Vladivostok. Earlier requests of the Japanese included solicitations for purchase of a modem Japanese battleship that are refused.

The primary reason for the Anglo-Japanese Alliance stemmed from a British need for naval support in parts of the Pacific Ocean to counter German naval capabilities in that region. Japan fulfilled that requirement and more. With the end of the war, the 1919 Peace Conference in Paris and the January 1920 Treaty of Versailles legitimized the wartime Japanese land expansion and initiated Japan’s acceptance as a world power. The German islands in the Pacific north of the equator were mandated to Japan with virtual sovereignty. 2 At this time, the Japanese Navy was third in the world.

The Peace Conference also established the League of Nations to work toward and implement international security to preclude conflict. During the negotiations for the League, Japan proffered a clause in the League’s covenant that would prohibit racial discrimination. It was rejected.

Japan’s participation in the war, although important and in some ways critical, was small in comparison with other warring nations from the viewpoints such as manpower involved, manpower and civilian losses and cost. Consequently, the participation of Japan on the side of the Allies is not frequently cited in historical writings about World War I. It is for this reason that the purpose of this article is to bring attention to some of the events demonstrating Japan’s role.

Anglo-Japanese Alliance Ends

The Washington Conference (1921-22)also known as the International Naval Conference on Naval Limitation included the signing on December 13, 1921 of the Four-Power Treaty between Great Britain, France, Japan and the United States. It provided that all the signatories would be consulted in the event of a controversy between two of them over .. any Pacific Question” 26 , and a pledge to respect each other’s rights in their island possessions in the Pacific. The replacing of the 1911 Anglo-Japanese Alliance by the new agreement was considered a major accomplishment.

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