"..the (Japanese) Navy General Staff sought as early as December (1941) to press for control over all of Australia as a major 'stage two' war objective."
From "Japan's Southward Advance and Australia" (1991), by distinguished Japan scholar and historian Professor Henry Frei (1991) at page 163.

"Underlying this basic (Navy) policy was support for the invasion of Australia, the main area from which the United States would launch counter-offensives against the Japanese."
From Senshi Sosho, the official Japanese war history published by the Japanese Defense Agency. See reference below.

"The Navy High Command wanted to invade Australia, in order to eliminate it as a potential springboard for a counter-offensive by the Allies, but the Army baulked at this because it would require an excessive commitment of manpower."
From "Japanese air operations over New Guinea during the Second World War" by Hiroyuki Shindo, Assistant Professor, Military History Department, National Institute for Defense Studies, Tokyo. The article was published in "Journal of the Australian War Memorial, June 2001, Vol. 34.


Admiral Osami Nagano, Japan's Chief of Navy General Staff, 1941-42
From December 1941 to early March 1942, Admiral Nagano advocated an early invasion of the northern Australian mainland and cutting Australia's lifeline to the United States. When the Japanese Army insisted that Australia's lifeline to the United States had to be cut and that Australia had to be "throttled" into complete submission to Japan, Admiral Nagano agreed to the Army's plan. Australia's complete surender to Japan was intended to be achieved by "Operation FS". See note on "Operation FS" in a later chapter.

In this history of the Battle for Australia all quotations from Senshi Sosho, the 102 volume official history of Japan's involvement in World War II, are drawn from the translations provided by Dr Steve Bullard and the cooperation of the Australia-Japan Research Project in providing access to those translations is acknowledged with deep appreciation.

Unless otherwise expressly stated, all references to "Professor Frei" or "Frei" are to the distinguished Japan scholar and historian Professor Henry Frei and his authoritative work "Japan's Southward Advance and Australia"(1991).


To prevent Australia becoming a base for the expected American counter-offensive following the treacherous Japanese attack on Pearl Harbor, Japan's Navy General Staff sought as early as December 1941 to press for control over Australia as a major "Stage Two" war objective.* The Navy General Staff planned to achieve this control of Australia by invading strategically important coastal areas of the northern Australian mainland and severing the lines of communication between Australia and the United States by blockade. In discussions between Operations chiefs of the Japanese Navy and Army from December 1941 to early March 1942, the senior generals made clear their objections to the Navy plan for limited invasions of the Australian mainland. The Japanese Army, and the Prime Minister of Japan, General Hideki Tojo, opposed the Navy's plan because they believed that invading and occupying only coastal areas of the northern Australian mainland would expose Japan to a lengthy war of attrition similar to the one that was tying down thirty Japanese divisions in China. The generals believed that the vast size of the Australian mainland would require commitment of at least ten Japanese Army divisions to crush all resistance. They argued that those ten divisions were needed in Manchukuo (formerly Chinese Manchuria) to guard against a Soviet advance into Manchukuo. They also argued that maintaining ten Japanese divisions on the Australian mainland would impose an impossible logistical burden on Japan's merchant fleet which was already heavily committed to transporting raw materials from the countries conquered by Japan in South-East Asia.

* See first quote at beginning of this chapter.

Japanese Army objections to a full-scale invasion of the Australian mainland in 1942 did not mean that the generals were blind to the danger from Australia as an American ally. As pointed out in the earlier chapter "Before Pearl Harbor, Japan targets Australia's New Guinea Territories", Imperial General Headquarters had approved the capture of the Australian-administered islands New Britain and New Ireland during the First Operational Stage of Japan's Pacific aggression. These two islands were part of Australia's League of Nations' New Guinea Mandate. After completion of the First Stage, Imperial General Headquarters had also approved the capture of Port Moresby in the Australian Territory of Papua and Tulagi in the British Solomon Islands. Sovereignty over Papua had been transferred by Great Britain to Australia in 1906, so it is clear that the Japanese were intending to invade sovereign Australian territory even before Pearl Harbor.

At an Imperial Liaison Conference held in Tokyo on 10 January 1942, the Japanese Army had supported a plan to isolate Australia from the United States known as Operation FS. The aim of this plan was to "throttle Australia into submission" to Japan. "Operation FS" involved the Japanese capturing a string of islands across the South Pacific from New Guinea to Fiji and Samoa. When these islands had been captured and fortified, the Japanese intended to impose a tight blockade of Australia and use powerful psychological pressures to persuade Australia to surrender. Presumably, these "psychological pressures" would have included greatly intensified bombing and shelling of Australian cities and towns, and sinking more Australian ships off the coast.

Immediately following the fall of Singapore on 15 February 1942, Army Chief of Staff General Sugiyama advised his Japanese Navy opposite number Admiral Nagano that there was a need "to reflect on the immense problem of how to control Australia...because if we only take one part of Australia, it will surely develop into a war of attrition...There are in-depth plans that consider the control of the entire continent, it is useless for us to plan for an invasion of only part of Australia." By "in-depth plans", General Sugiyama was referring to Operation FS. See Professor Henry Frei, "Japan's Southward Advance and Australia" (1991) at pages 166-167.

On 4 March 1942, at a meeting of the Army and Navy Sections of Imperial General Headquarters, the Japanese Navy agreed that the Army plan to isolate and blockade Australia with a view to compelling Australia's surrender to Japan by means of Operation FS was the better one. The Navy plan for limited invasion of the Australian mainland was deferred at that conference, with agreement that the Navy invasion plan for the Australian mainland would be further studied by both Navy and Army Sections. This agreement was formally ratified at an Imperial Liaison Conference on 11 March 1942, and it was presented to Emperor Hirohito on 13 March 1942. After receiving the emperor's approval, on 15 March 1942 Imperial General Headquarters ordered the Japanese Army and Navy to implement Operation FS .

In the Japanese Parliament (called the Diet), Prime Minister General Hideki Tojo had demanded that Australia surrender to Japan in January and February 1942. His demands for Australian surrender were ignored by the Curtin Government. In the confident expectation that Operation FS would produce Australia's surrender to Japan, Prime Minister Tojo had already set in place long-term planning for inclusion of Australia as a puppet state in Japan's Greater East Asia Co-Prosperity Sphere. The distinguished Japan scholar and historian Professor Henry Frei has confirmed this sequence of events in his authoritative history "Japan's Southward Advance and Australia" (1991) at page 172. Professor Frei's account of Japan's hostile planning for Australia in 1942 is supported by the official Japanese history Senshi Sosho.

It is difficult to see how an Australian surrender to Japan, of the kind contemplated by the generals, could be meaningful without some form of Japanese occupation that would exclude access to Australia by the United States.

In a series of crucial battles between 15 March 1942 and 7 February 1943, Australian and American forces desperately struggled to prevent Japan implementing Operation FS, and they succeeded.

Japan's Navy General Staff and Navy Ministry press for a limited invasion of the Australian mainland in early 1942

Although Combined Fleet appeared to have taken the initiative in planning offensive options for the Second Operational Stage of Japan's military aggression in 1942, Navy General Staff had not been idle in the weeks that followed Pearl Harbor. With Japanese-occupied island chains and the powerful Japanese Navy blocking direct access by the United States Navy to relieve the beleaguered American garrison in the Philippines, Japan's Navy General Staff appreciated that Australia’s survival as a free nation and ally would be of vital importance to the United States.

Chief of the Plans Division of the powerful First Section (Operations) of Navy General Staff, Captain Sadatoshi Tomioka, said after the war, "What I worried about most was Australia".* He knew that America's military strength would expand enormously by 1943, but as long as that colossal military strength was pinned down on the Hawaiian Islands and in the United States, he believed that Japan could hold its conquered Pacific territories. Tomioka believed that American air power would be ineffective without forward air bases from which aircraft could operate. However, with Australia as a gigantic forward base, the Americans would be able to deploy their massive military strength within striking distance of Japan's southern defensive perimeter and use the islands of the South-West Pacific as stepping stones to recover the Philippines and then move against Japan's home islands. As indicated above, the Second Operational Stage of Japan's Pacific aggression would push Japan's southern defensive perimeter to Port Moresby in the Australian sovereign Territory of Papua acquired from Great Brtain in 1906.

* Frei, at p. 162. Tomioka was promoted to admiral, and participated in the signing of the peace treaty aboard USS Missouri in Tokyo Bay.

To remove this danger to Japan's southern defensive perimeter, Captain Tomioka argued that it was not sufficient to isolate Australia from the United States by blockade; Japan must also invade and occupy key areas of the Australian mainland. Tomioka won powerful support when this argument was accepted by the Chief of the Navy General Staff, Admiral Osami Nagano.

A proper appreciation of the structure and functioning of Japan's military high command in 1941-42, and the relationship between Imperial Japanese Army and Navy, should leave no doubt that when Professor Frei uses the term "Navy General Staff" in this and the following passages, it represents the views of Chief of Navy General Staff (Admiral Nagano) himself:

"To prevent this (Australia becoming a base for the American counter-offensive), the Navy General Staff sought as early as December to press for control over all of Australia as a major 'stage two' war objective. This would be achieved by invading the strategically most important points on the northern and north-eastern coasts of Australia. Japan would there annihilate the enemy's maritime forces, cut the American-Australian line of communication, and thereby deal the entire Australian nation a thorough blow....The Navy General Staff calculated in its early requests in December 1941 that three divisions (between 45,000 and 60,000 men) would suffice to capture and annihilate the Australian fleet and to secure the flanks and center of the northeastern and northwestern Australian coastlines." See Frei, at pages 163-164. The emphasis is mine.

Although the historical evidence points clearly to a limited invasion of the Australian mainland having been planned and approved at the highest levels of Japan's Navy General Staff and Navy Ministry in 1941 and early 1942, it is necessary at this point to raise and squash a bizarre claim that has been promoted by Dr Peter Stanley of the Australian War Memorial. Dr Stanley has claimed since 2002 that any proposal to invade Australia in 1942 was limited to discussions between "middle-ranking naval staff officers" and did not proceed above that level. To the best of my knowledge, Dr Stanley has produced no credible historical evidence to support this claim, and it appears to be supported only by those with inadequate knowledge of the dynamics of the Pacific War in 1942. Dr Stanley initially claimed that the distinguished Japan scholar Professor Henry Frei supported his controversial revisionism, but when I pointed out in letters to newspapers and on this web-site that Professor Frei's authoritative work "Japan's Southwards Advance and Australia" directly contradicted Dr Stanley's revisionist views on this theme, Dr Stanley withdrew his claim that Professor Frei supported him. For a detailed treatment of Dr Stanley's revisionist claims on this theme see the chapter "Dr Peter Stanley showcases his ignorance of the Pacific War". I am frankly surprised to find the Australia's national war memorial still displays a text exhibit that contains numerous significant historical errors.

It is quite absurd for Dr Stanley to suggest that "middle-ranking naval staff officers" could make requests for "three divisions" from the Imperial Japanese Army. Only the Chief of Navy General Staff Admiral Nagano could make such a request. Further proof that the references to "Navy General Staff" in the passage above are not to "middle-ranking naval staff officers" but to the Chief of the Japanese Navy is provided by Professor Frei in the following passage:

"Luckily for Australia, however, the Japanese army always opposed as too low the navy's estimated number of soldiers needed for an invasion. Time and again the army insisted that it would take take at least ten divisions (between 150,000 and 200,000 men), maybe twelve, to invade Australia." See Frei at page 164. The emphasis is mine.

References to "navy" and "army" in the immediately preceding passage could not be to "middle-ranking" staff officers. The views expressed in this passage would have to be those of the Chiefs of Army and Navy General Staff.

Further confirmation that planning to invade Australia reached the highest level of the Japanese Navy in early 1942 is provided by Professor Frei in his treatment of the Dutch and Australian occupation of Portuguese Timor:

"Disposal of this neutral speck of Portuguese territory with an enemy presence drew heated discussions in the war council. The army pleaded for withdrawal after a cleansing operation, but the navy wanted to retain Portuguese Timor as a forward base in a future attack against Port Darwin and for purposes of invasion. To this end, the Dutch and Australian presence offered a welcome pretext to establish an operational base there by force. Prime Minister Tojo Hideki was totally opposed to Chief of Navy General Staff Nagano Osami in the dispute that raged in the Diet and at the Liaison Conferences from 21 to 31 January 1942." See Frei at page 170. The emphasis is mine.

When the easy capture of Rabaul on 23 January 1942 demonstrated the weakness of Australia's defences, middle-ranking officers of Navy General Staff and Navy Ministry began to urge upon their Army counterparts the need for an early invasion of the Australian mainland. Professor Frei records some of these vigorous debates, but he takes care to indicate that they involved only middle-ranking officers. See Frei, at last paragraph on page 165 to second last paragraph on page 166.

Perhaps the most compelling evidence of Japan's hostile plans for Australia in 1942 can be found in the official Japanese history of the Pacific War Senshi Sosho. Dr Steven Bullard, a Senior Historian and specialist Japan scholar at the Australian War Memorial, translated and published in 2007 the sections of Senshi Sosho that contained the Japanese high command's strategic planning to deal with Australia in 1942. The Bullard translation records a decision taken by Japan's military high command in January 1942 to:

"Proceed with the Southern Operations, all the while blockading supply from Britain and the United States and strengthening the pressure on Australia, ultimately with the aim to force Australia to be freed from the shackles of Britain and the United States".