Planned invasion of Australia during World War II

In early 1942 elements of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

(IJN) proposed an invasion of Australia. This proposal was opposed by the Japanese Army

Imperial Japanese Army

-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...

and was rejected in favour of a policy of attacking Midway Island

Midway Atoll

Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

and isolating Australia from the United States via blockade by advancing through the South Pacific

Oceania

Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...

Debate between the Army and Navy

Japan's success in the early months of the Pacific War

Pacific War

The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

led elements of the IJN to propose invading Australia. In December 1941 the Navy proposed including an invasion of Northern Australia

Northern Australia

The term northern Australia is generally known to include two State and Territories, being Queensland and the Northern Territory . The part of Western Australia north of latitude 26° south—a definition widely used in law and State government policy—is also usually included...

as one of Japan's 'stage two' war objectives after South-East Asia was conquered. This proposal was most strongly pushed by Captain Sadatoshi Tomioka

Sadatoshi Tomioka

- Notes :...

, the head of the Navy General Staff's Planning section, on the grounds that the United States was likely to use Australia as a base to launch a counter-offensive in the South-West Pacific. The Navy headquarters argued that this invasion could be carried out by a small landing force as this area of Australia was lightly defended and isolated from Australia's main population centres. There was not universal support for this proposal within the Navy, however, and Isoroku Yamamoto

Isoroku Yamamoto

was a Japanese Naval Marshal General and the commander-in-chief of the Combined Fleet during World War II, a graduate of the Imperial Japanese Naval Academy and a student of Harvard University ....

, the commander of the Combined Fleet

Combined Fleet

The was the main ocean-going component of the Imperial Japanese Navy. The Combined Fleet was not a standing force, but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime....

, consistently opposed it.

The Japanese Army opposed the Navy's proposal as being impractical. The Army's focus was on defending the perimeter of Japan's conquests, and it believed that invading Australia would over-extend these defence lines. Moreover, the Army was not willing to release the large number of troops it calculated were needed for such an operation from the Kwantung Army in Manchuria

Manchuria

Manchuria is a historical name given to a large geographic region in northeast Asia. Depending on the definition of its extent, Manchuria usually falls entirely within the People's Republic of China, or is sometimes divided between China and Russia. The region is commonly referred to as Northeast...

as it both feared that the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

would enter the Pacific War and wanted to preserve an option for Japan to invade Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

.

Prime Minister

Prime Minister of Japan

The is the head of government of Japan. He is appointed by the Emperor of Japan after being designated by the Diet from among its members, and must enjoy the confidence of the House of Representatives to remain in office...

Hideki Tojo

Hideki Tōjō

Hideki Tōjō was a general of the Imperial Japanese Army , the leader of the Taisei Yokusankai, and the 40th Prime Minister of Japan during most of World War II, from 17 October 1941 to 22 July 1944...

also consistently opposed invading Australia. Instead, Tojo favoured a policy of forcing Australia to submit by cutting its lines of communication with the US. In his last interview before being executed for war crimes Tojo stated that:

We never had enough troops to do so [invade Australia]. We had already far out-stretched our lines of communication
Lines of Communication
"Lines of Communication" is an episode from the fourth season of the science-fiction television series Babylon 5.-Synopsis:Franklin and Marcus attempt to persuade the Mars resistance to assist Sheridan in opposing President Clark...

. We did not have the armed strength or the supply facilities to mount such a terrific extension of our already over-strained and too thinly spread forces. We expected to occupy all New Guinea, to maintain Rabaul
Rabaul
Rabaul is a township in East New Britain province, Papua New Guinea. The town was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash of a volcanic eruption. During the eruption, ash was sent thousands of metres into the air and the...

as a holding base, and to raid Northern Australia by air. But actual physical invasion — no, at no time.

In speeches before the Diet on 12 January and 16 February 1942, Tojo stated Japanese policy was to: "eradicate the British colonies at Hong Kong

Hong Kong

Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

and in the Malay peninsula

Malay Peninsula

The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...

as these were "evil bases used against East Asia", and turn these places into strongholds for the defence of Greater East Asia. Burma and the Philippines would get independence if they co-operated with Japan; the Netherlands East Indies and Australia would be crushed if they resisted; but if they recognised Japan's true intentions would receive help in promoting their welfare and development."

The Army and Navy's calculations of the number of troops needed to invade Australia differed greatly and formed a central area of discussion. In December 1941 the Navy calculated that a force of three divisions

Division (military)

A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...

(between 45,000 and 60,000 men) would be sufficient to secure Australia's north-eastern and north-western coastal areas. In contrast, the Army calculated that a force of at least ten divisions (between 150,000 and 250,000 men) would be needed. The Army's planners estimated that transporting this force to Australia would require 1.5 to 2 million tons of shipping, which would have required delaying the return of requisitioned merchant shipping. This invasion force would have been larger than the entire force used to conquer South-East Asia. The Army also rejected the Navy's proposal of limiting an invasion of Australia to securing enclaves in the north of the country as being unrealistic given the likely Allied counter-offensives against these positions. Due to its experience in China

Second Sino-Japanese War

The Second Sino-Japanese War was a military conflict fought primarily between the Republic of China and the Empire of Japan. From 1937 to 1941, China fought Japan with some economic help from Germany , the Soviet Union and the United States...

the Army believed that any invasion of Australia would have to involve an attempt to conquer the entire Australian continent, something which was beyond Japan's abilities.

The possibility of invading Australia was discussed by the Japanese Army and Navy on several occasions in February 1942. On 6 February the Navy Ministry formally proposed a plan in which eastern Australia would be invaded at the same time other Japanese forces captured Fiji

Fiji

Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

, Samoa

Samoa

Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...

and New Caledonia

New Caledonia

New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...

, and this was again rejected by the Army. On 14 February, the day before Singapore was captured

Battle of Singapore

The Battle of Singapore was fought in the South-East Asian theatre of the Second World War when the Empire of Japan invaded the Allied stronghold of Singapore. Singapore was the major British military base in Southeast Asia and nicknamed the "Gibraltar of the East"...

the Army and Navy sections of the Imperial General Headquarters

Imperial General Headquarters

The as part of the Supreme War Council was established in 1893 to coordinate efforts between the Imperial Japanese Army and Imperial Japanese Navy during wartime...

again discussed invading Australia and during this discussion Captain Tomioka argued that it would be possible to take Australia with a "token force". This statement was labelled "so much gibberish

Gibberish

Gibberish is a generic term in English for talking that sounds like speech, but carries no actual meaning. This meaning has also been extended to meaningless text or gobbledygook. The common theme in gibberish statements is a lack of literal sense, which can be described as a presence of nonsense...

" in the Imperial General Headquarters' secret diary. General Tomoyuki Yamashita:

He said that after he had taken Singapore, he wanted to discuss with Tojo a plan for the invasion of Australia …Tojo turned down the plan, making the excuse of lengthened supply lines, which would be precarious and open to enemy attack…"

The dispute between the Army and Navy was settled in late February with a decision to isolate rather than invade Australia. The Army continued to maintain its view that invading Australia was impractical, but agreed to extend Japan's strategic perimeter and cut Australia off from the US by invading Fiji

Fiji

Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

, Samoa

Samoa

and New Caledonia

New Caledonia

in the so-called Operation FS

Operation FS

Operation FS was the name of the Imperial Japanese plan to invade and occupy Fiji, Samoa, and New Caledonia in the south Pacific during the Pacific conflict of World War II...

. The question of whether to invade Australia was discussed by Imperial Headquarters for the last time on 27 February and in this meeting the Army stated that it believed that Australia was defended by a 600,000-strong military force. During a further meeting held on 4 March the Imperial Headquarters formally agreed to a "Fundamental Outline of Recommendations for Future War Leadership" which relegated the option of invading Australia as a "future option" only if all other plans went well. This plan was presented to the Emperor by Prime Minister Hideki Tōjō

Hideki Tōjō

and in effect ended discussion of invading Australia. The FS Operation was not implemented, however, due to Japan's defeats in the Battle of the Coral Sea

Battle of the Coral Sea

The Battle of the Coral Sea, fought from 4–8 May 1942, was a major naval battle in the Pacific Theater of World War II between the Imperial Japanese Navy and Allied naval and air forces from the United States and Australia. The battle was the first fleet action in which aircraft carriers engaged...

and Battle of Midway

Battle of Midway

The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

and was canceled on 11 July 1942.

Subsequent Japanese operations in the South-West Pacific

As the option of invading Australia was rejected in February 1942 and was not revisited, the Japanese attacks on Australia

Attacks on Australia during World War II

Due to Australia's geographic position there were relatively few attacks on Australia during World War II. Axis surface raiders and submarines periodically attacked shipping in Australian waters from 1940 to early 1945 and Japanese aircraft bombed towns and airfields in Northern Australia on 97...

during the war were not precursors to invasion as is sometimes claimed. The large air raid on Darwin on 19 February 1942 and the Attack on Broome

Attack on Broome

The town of Broome, Western Australia was attacked by Japanese fighter planes on 3 March 1942, during World War II. At least 88 people were killed....

on 3 March were conducted to prevent the Allies

Allies of World War II

The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

from using these towns as bases to contest the invasion of the Netherlands East Indies

Dutch East Indies campaign

The Dutch East Indies campaign of 1941–1942 was the conquest of the Dutch East Indies by forces from the Empire of Japan in the early days of the Pacific Campaign of World War II. Forces from the Allies attempted unsuccessfully to defend the islands. Indonesia was targeted by the Japanese for its...

and was not related to an invasion. According to Frei:

The generals of the Army General Staff, and the Prime Minister of Japan, General Hideki Tojo, did not see a need to commit massive troop resources to the conquest of Australia, with the massive logistical problems that would produce. The generals were confident that Australia could be bullied into surrender to Japan by isolating it completely from the United States and by applying intense psychological pressure."

The dozens of subsequent air raids on Northern Australia in 1942 and 1943 were mainly small and aimed to prevent the Allied air units based there from attacking Japanese positions. The Attack on Sydney Harbour

Attack on Sydney Harbour

In late May and early June 1942, during World War II, submarines belonging to the Imperial Japanese Navy made a series of attacks on the cities of Sydney and Newcastle in New South Wales, Australia...

in May 1942 had the goal of diverting Allied forces away from Midway Island

Midway Atoll

prior to the Japanese attempt to capture it and the subsequent Japanese submarine campaigns

Axis naval activity in Australian waters

Although Australia was remote from the main battlefronts, there was considerable Axis naval activity in Australian waters during the Second World War. A total of 54 German and Japanese warships and submarines entered Australian waters between 1940 and 1945 and attacked ships, ports and other targets...

off the Australian east coast in 1942 and 1943 were attempts to break the supply line between Australia and New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

during the New Guinea Campaign

New Guinea campaign

The New Guinea campaign was one of the major military campaigns of World War II.Before the war, the island of New Guinea was split between:...

. Moreover, the Japanese attempt to capture Port Moresby

Port Moresby

Port Moresby , or Pot Mosbi in Tok Pisin, is the capital and largest city of Papua New Guinea . It is located on the shores of the Gulf of Papua, on the southeastern coast of the island of New Guinea, which made it a prime objective for conquest by the Imperial Japanese forces during 1942–43...

in New Guinea by advancing along the Kokoda Track

Kokoda Track campaign

The Kokoda Track campaign or Kokoda Trail campaign was part of the Pacific War of World War II. The campaign consisted of a series of battles fought between July and November 1942 between Japanese and Allied—primarily Australian—forces in what was then the Australian territory of Papua...

and landing at Milne Bay

Battle of Milne Bay

The Battle of Milne Bay, also known as Operation RE by the Japanese, was a battle of the Pacific campaign of World War II. Japanese marines attacked the Australian base at Milne Bay on the eastern tip of New Guinea on 25 August 1942, and fighting continued until the Japanese retreated on 5...

between July and September 1942 aimed to capture the town to complete Japan's defensive perimeter in the region. Once secured, Port Moresby was to have been used as a base from which Japanese aircraft could dominate the Torres Strait

Torres Strait

The Torres Strait is a body of water which lies between Australia and the Melanesian island of New Guinea. It is approximately wide at its narrowest extent. To the south is Cape York Peninsula, the northernmost continental extremity of the Australian state of Queensland...

and Coral Sea

Coral Sea

The Coral Sea is a marginal sea off the northeast coast of Australia. It is bounded in the west by the east coast of Queensland, thereby including the Great Barrier Reef, in the east by Vanuatu and by New Caledonia, and in the north approximately by the southern extremity of the Solomon Islands...

, and not to support an invasion of Australia.

The only Japanese force which landed in Australia during the war was a small reconnaissance party which landed in the remote Kimberley region of Western Australia on 19 January 1944 to investigate reports that the Allies were building large bases in the region. This party consisted of four Japanese officers on board a small fishing boat and it investigated the York Sound region for a day and a night before returning to Kupang in Timor

Timor

Timor is an island at the southern end of Maritime Southeast Asia, north of the Timor Sea. It is divided between the independent state of East Timor, and West Timor, belonging to the Indonesian province of East Nusa Tenggara. The island's surface is 30,777 square kilometres...

on 20 January. While the junior officer who commanded the party suggested using 200 Japanese prison inmates to launch a guerrilla campaign in Australia when he returned to Japan in February, nothing came of this and the officer was posted to other duties. According to historian Peter Stanley

Peter Stanley

Dr Peter Stanley is an Australian historian. He is Head of the Centre for Historical Research at the National Museum of Australia. Between 1980 and 2007 he was an historian and curator at the Australian War Memorial, including as head of the Historical Research Section and Principal Historian...

"No historian of standing believes the Japanese had a plan to invade Australia, there is not a skerrick of evidence."

Debate between the Army and Navy

Subsequent Japanese operations in the South-West Pacific

See also