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1919 - Treaty of Versailles - Japan is granted a mandate over the ex-German islands in the Pacific. The League of Nations is formed.

1921-22 - Washington Naval Treaty - Britain, United States, Japan, France and Italy agree to limit the displacement and main armament of capital ships, aircraft carriers and cruisers, and total tonnage and age of the first two categories.

1922 - Japanese carrier "Hosho" completed.

1927 - Geneva Naval Conference fails to reach agreement on total tonnage of cruisers, destroyers and submarines.

Major warships completed include Japanese carrier "Akagi".

1928 - Japanese carrier "Kaga" completed

1930 - London Naval Treaty - Britain, US and Japan agree on total tonnage, tonnage and armament limitations for cruisers, destroyers and submarines. Also that no new capital ships are to be laid down until 1937.

1931 - An incident in the Chinese province of Manchuria leads to the Japanese invasion which is completed by early 1932. The puppet state of Manchukuo is declared. By then Japanese forces have taken control of the Shanghai area in further fighting.

1933 - Japanese walk out of the League of Nations over the Manchurian issue.

Major warships completed include Japanese carrier "Ryujo".

1934 - The 1932 Geneva Disarmament Conference finally breaks down and Japan announces its intention to withdraw from the 1922 and 1930 Naval Treaties when they expire in 1936. Planning starts on the giant battleships of the "Yamato" class.

1935 - April - The United States passes the Neutrality Act forbidding the supply of arms to belligerents in the event of war.

1936 - November - London Protocol -The major powers including Germany agree to prohibit unrestricted submarine warfare against unarmed ships.

December -The 1922 and 1930 Naval Treaties are allowed to lapse and the major powers move towards rearmament.

1937 - July - Further incidents in China this time near Peking, lead to Japan extending its hold over northeastern China.

Major warships completed include Japanese carrier "Soryu".

1938 - By the end of 1938, Japan has completed its hold over northeastern China and the major port areas .

1939 - September 1st - Germany invades Poland; 3rd - Britain and France declare war on Germany

Major warships completed to 3rd September 1939 include Japanese carrier "Hiryu". Launched in the same period - Japanese carrier "Shokaku"


MARCH 1940

Steps to War with Japan - Japan establishes a Chinese puppet-government in Nanking.

JUNE 1940

Italy Declares War - Italy declares war on Britain and France on the 10th. Two weeks later France is out of the war. Still on the 10th, Australia, Canada, India, New Zealand and South Africa declare war on Italy.

Steps to War with Japan, June/July - With its possession of the Chinese ports, Japan wants to close the remaining entry points into China. Pressure is put on France to stop the flow of supplies through Indochina, and on Britain to do the same with the Burma Road. Both comply, but Britain does so only until October 1940, when the road is reopened.


Axis Powers - Germany, Italy and Japan sign the Tripartite Pact in Berlin on the 27th. They agree to jointly oppose any country joining the Allies at war - by which they mean the United States.

Steps to War with Japan - Vichy France finally agrees to the stationing of Japanese troops in northern Indochina.


Fleet Air Arm Attack on Taranto - On the 11th in the Mediterranean, British carrier "Illustrious" launches a Swordfish torpedo biplane attack on the main Italian naval base. Of the six battleships present, the 20 aircraft hit "CONTE DI CAVOUR" and "CAIO DIULIO" with one torpedo each and the brand new "LITTORIA" with three. All three sink at their moorings and "Cavour" is never recommissioned, all for the loss of just two Swordfish. The Japanese Navy studies the attack carefully as Pearl Harbor learns to its cost just a year later.


APRIL 1941

Steps to War with Japan - Five Year Neutrality Pact between Japan and Russia benefits both powers. Russia can free troops for Europe and Japan concentrate on her expansion southwards.

JULY 1941

Steps to War with Japan - The demand for bases in southern Indochina is now conceded by Vichy France. Britain, Holland and the United States protest and freeze Japanese assets, but the troops go in. The Dutch East lndies cancels oil delivery arrangements and the Americans shortly impose their own oil embargo. Japan has lost most of its sources of oil.


Steps to War with Japan - Japan and the US continue to negotiate over their differences, but as its oil stocks rapidly decline Japan accelerates preparations for war.


Steps to War with Japan - War Minister Gen Tojo becomes Japanese Prime Minister.


3rd - The recently completed British fleet carrier "Indomitable" runs aground and is damaged off Kingston, Jamaica. She is due to accompany capital ships "Prince of Wales" and "Repulse" to the Far East as a deterrent to Japanese aggression. Her absence in December may have proved fatal to the two big ships.

Steps to War with Japan - As talks drag on and the United States demands the departure of Japan from China as well as French Indochina, the Pearl Harbor Strike Force sails into the North Pacific. Vice-Adm Nagumo commands the fleet carriers "Akagi", "Hiryu", "Kaga", "Soryu", "Shokaku" and "Zuikaku", plus two battleships, cruisers and destroyers. Britain's limited naval deterrent to Japanese expansion, capital ships "Prince of Wales" and "Repulse" meet at Colombo, Ceylon on the 28th, en route to Singapore. Without the fleet carrier "Indomitable" they have no ship-borne aircraft support.



Starting Conditions - Strategic and Naval Background



Britain and Dominions - Responsible for defending India, Ceylon, Burma, Malaya, northern Borneo, Hong Kong, Australia, New Zealand, the Papua New Guinea/Bismarck Archipelago/Solomon Islands chain, and numerous island groups throughout the Indian Ocean and Central and South Pacific.

Few forces can be spared from existing war zones to protect this vast spread of territory and its supply routes. Britain's main base is at Singapore with its two recently arrived big ships. Three old cruisers and some destroyers are in Malayan waters, and a few old destroyers at Hong Kong. By now the surviving seven cruisers and smaller ships of the Royal Australian and New Zealand Navies are back in the area.


United States - Apart from the defence of its Western seaboard, Panama Canal Zone, Alaska and the Aleutians, Hawaiian Islands and various islands in the Central Pacific, the US has responsibilities towards the Philippines. In the event of attack, the defenders are expected to hold out until relieved by the US Pacific Fleet fighting its way from the main base at Pearl Harbor, a distance of 4,500 miles.

In the Philippines is the Asiatic Fleet with three cruisers, 13 destroyers and 29 submarines.

The Pacific Fleet itself consists of eight battleships, three fleet carriers, 21 cruisers, 67 destroyers and 27 submarines.

Dutch - Naval forces allocated to the defence of the many islands of the Dutch East lndies include three cruisers, seven destroyers and fifteen submarines.


Already established in Korea, Manchuria, northeast China, its main ports and Hainan, Formosa, and the Mariana, Caroline and Marshall Island groups, Japan now has the whole of French Indochina.

Japan's main aim is still the conquest of China, for which the oilfields of the Dutch East lndies (DEI) are indispensable. Also important is the closing of the Burma Road over which Allied supplies continue to roll.

Both moves mean war with Britain and the US, and a vital part of the Japanese strategy is the establishment of a huge defence perimeter stretching from Burma right around to the Aleutian Islands of Alaska. Only in this way can it hope to hold off the United States once its manpower and industrial resources are mobilised.

Japan goes to war with both the strategic and military advantages:

Strategically -

Japan is well placed to occupy the territory needed for the defence perimeter:

In the West - much of China is occupied and the Neutrality Pact with Russia, coupled with the German invasion means Japan has little to fear for now from this direction. Hong Kong can be taken easily from adjacent occupied China


To the East are the vast distances of the Pacific. By taking the US islands of Guam and Wake, and some of the British Gilbert Islands, the mandated islands (Marshalls, Caroline's, Marianas) are further protected. America is also kept at bay.

To the Southwest
- Thailand and Malaya will soon fall to the invading forces from Hainan and Indochina. Thereafter the capture of Burma can proceed smoothly. The Burma Road will be cut, India threatened, and that perimeter is secured.


In the South - lay the oilfields of the Dutch East Indies and the protection offered by the island chain of Sumatra, Java and Bali through to Timor. The main island of Java is the target of two massive pincer movements:

- landings in north New Guinea, the Bismarck Archipelago and northern Solomons will protect the Japanese Carolines. From there, forces can strike Australia and its supply routes.



Westwards - From Indochina to northern Borneo, and later direct to Sumatra and Java.


Eastwards - From bases in Formosa and the Carolines to the Philippines. From there to southern Borneo, Celebes and Moluccas, and on to Timor and Bali. Then to eastern Java.


Only when Japan seeks to extend the southeast and eastern perimeters - at Guadalcanal and Midway Island respectively in mid-1942 does it suffer the first defeats. America's growing power will then make Allied victory inevitable.

Militarily -

Allied and Japanese naval forces are about balanced in numbers:

Major Warship types

















































There the comparison ends .....

The Imperial Japanese Navy has far more carriers, its surface task forces are well trained, especially in night-fighting, and they have no command or language difficulties. They also introduce the Allies to a secret and powerful weapon in the 24in Long lance torpedo. In contrast, the Allied ships are scattered and have no central command. Their main bases at Singapore and Pearl Harbor are 6,000 miles apart, and most of the strength is concentrated with the US Pacific Fleet.

For its conquests, the Japanese Army fields only slightly more troops, but these are usually better trained, and also experienced in amphibious operations. They have air superiority both overall and locally. Only the US Pacific Fleet poses an immediate danger to Japanese plans. Hence the decision to attack it in Pearl Harbor rather than wait for it to try to fight through to the Philippines.

The Japanese choose the time and place of their landings, ail well escorted by cruiser and destroyer forces. Air cover is maintained by land-based aircraft or from carriers and seaplane carriers as necessary, and battleships and cruisers provide distant support. By this time the annihilation of the Allied capital ships will make their presence unnecessary.

The few Allied maritime sorties - some surface, but mainly by aircraft and submarine - have few successes against the invasion fleets. And in return they suffer heavy losses.

Declarations and Outbreak of War - Because of the International Dateline, events that take place on the 7th in Hawaii as far as Washington and London are concerned, are already into the 8th in Hong Kong and Malaya. By the 8th:

 - Japan has declared war on Britain and the US.

 - Britain, Australia, Canada, New Zealand, South Africa, Holland, the United States and a number of Central American and Caribbean states have declared against Japan.

 - China declares war against the Axis powers.

Continuing to use the compass directions outlining the Japanese strategy in “Starting Conditions“ above , attacks in December 1941 proceed as follows:

West - Hong Kong - The territory is invaded from mainland China on the 8th December, and within five days the defenders have withdrawn to Hong Kong Island. Fighting carries on until Christmas Day when the British and Dominion troops surrender.

Destroyer “THRACIAN” is bombed in defence of the colony and later beached and abandoned. She is re-commissioned into the Japanese Navy as a patrol boat.

South West - Thailand, Malaya, Burma - Japanese forces land on the Kra Isthmus of Thailand and northeast Malaya on the 8th. From there they drive down the west coast of Malaya towards Singapore, outflanking the defences by land and sea. Follow-up landings take place later in the month and in January 1942. By the 13th December they have crossed from Thailand into the southern tip of Burma, but stay there for the time being.

10th - Loss of “Repulse” and “Prince of Wales”: the Sinking of Force Z - By the 8th, the battlecruiser and battleship have assembled at Singapore as Force Z under the command of Adm Sir Tom Phillips. That evening they sail with four destroyers to attack the Japanese landing on the northeast Malay coast. Fighter cover is requested but is not readily available.

In the evening of the 9th, Force Z is well up into the South China Sea. Japanese aircraft are spotted and Adm Phillips decides to return. Around midnight he receives a false report of landings at Kuantan, further down the Malay Peninsular and sets course for there. The ships have by now been reported by a submarine, and a naval aircraft strike force is despatched from Indochina. Attacks start around 11.00 on the 10th December, and in less than three hours “PRINCE OF WALES” and “REPULSE” have been hit by a number of torpedoes and sent to the bottom. Nearly a thousand men are lost, but 2,000 are picked up by the destroyers.

Following the Pearl Harbor attack, not one of the Allies' 10 battleships in the Pacific area remain in service.

South - Northern Borneo and Philippines Islands - The first landings in northern Borneo take place in Sarawak and Brunei on the 16th December, and continue through until late January 1942. In the Philippines, the island of Luzon is the main target. Between the 10th and 22nd, landings are made in the north of the island, in the south, and at Lingayen Gulf in the west. The Japanese forces make a combined drive on the capital of Manila, which is declared an open city. They enter on 2nd January 1942 by which time preparations are being made to attack Gen MacArthur's US and Filipino troops now withdrawn into the Bataan Peninsular just to the west of Manila. The southern island of Mindanao is invaded on 20th December 1941.

East - Hawaiian Islands, Guam, Wake Island and British Gilbert Islands - On the morning of the 7th local time (shortly after the Malay landings) the Japanese Strike Force aircraft hit Pearl Harbor on the Hawaiian island of Oahu. In the Attack on Pearl Harbor, battleships “ARIZONA” and “OKLAHOMA” are total losses, three more sink but are later re-commissioned, and the remaining three damaged. Many are killed and a considerable number of aircraft destroyed. Although the Pacific battlefleet ceases to exist, the three priceless fleet carriers “Enterprise”, “Lexington” and “Saratoga” are fortunately absent and the large oil stocks and important repair installations left virtually untouched. By the 10th, Guam in the Mariana Islands is captured and Makin and Tarawa in the British Gilberts occupied. Tarawa is then abandoned until the following September 1942. Wake Island is attacked on the 11th December, but the Japanese are driven off with the loss of two destroyers by the US Marine defenders. A later attempt on the 23rd succeeds.

Monthly Loss Summary
Indian Ocean - 5 merchant ships of 800 tons
Pacific Ocean - 241 merchant ships of 432,000 tons