Why are the Allies so unready for war with Japan in 1942?

Why does Japan in 1942 have so much edge against the Allies? Multiple rapid and successful campaigns and long range seaborn invasions should have met more resistance. Why did the Japanese have such an early advantage? Why were the Allies apparently quite so incompetent?


The same issue applies to the European allied forces.
It is a complex question to answer and I commend you on starting up this topic :+1:
I believe both Japan and Germany were gambling on a swift victory by delivering a deadly blow.
They both failed, simply because they underestimated the biggest warwinning factor: the war industry of the USA


There are many reasons and factors in this question some of which have been touched on by Indy’s weekly series.

Most of the allied nations with assets in the region felt the Japanese were inferior in tactics and equipment. Even in the early stages of the conflict even though the evidence was mounting on superior Japanese tactics and overwhelming AirPower many commanders and even politicians back in Europe and the US had trouble comprehending the evidence that was laid out before them.

Add to that many forces that were opposing the Japanese were undermanned and inexperienced in war whereas the Japanese already had 5 years worth of experience in China. The Japanese also had air superiority in the region which goes a long way to controlling the seaways and battlefields.

The downfall for the Japanese was multi-pronged with the Japanese navy, army and airforce constantly bickering with each other, countermanding each other’s orders and having to defend such a large amount of ocean with limited naval assets. Add to that the US was slowly gearing up their war factories and manpower.

There are many other reasons that Japan had early successes and this is a very expansive subject in itself.


My point is that we see Japan invade Wake Island, Guam, Hong Kong, Malaysia/Singapore, multiple islands in the Philipines and the Dutch East Indies, Rabaul, Burma and Thailand, in a very short space of time. Japan also emerges victorious from every invasion. Japan encounters significant difficulty only in the Philipines, and even there, the USA gives up Manilla and Clark Field very quickly to head for the Bataan Peninsula. This is in many ways more impressive than anything Germany has managed to date.

Every naval landing is potentially a D-Day Omaha Beach event for the invaders, and when the USA tries the same in reverse, Japan turns every island hop into a meat grinder. How did Japan manage to “invent” themselves a long range Empire by sea invasion in 2 months tops when it took Britain centuries?

Can we realistically put this all down to superior Japanese access to airpower as the major obvious difference between the forces? Consider, green troops throughout history often rise to the occasion, and even veterans can break. Now Pearl Harbor had happened, so surprise should not have been a factor, and even a fiercely incompetent commander can generally figure out how to defend a hardpoint or two, even from air attack.

Now had the Japanese invaded these places unopposed it might have been understandable, but their targets were important installations such as oilfields, cities and airfields, and they were defended positions. My instincts tell me that something crucial has been missed, or heavily underplayed and undervalued in this history. Sea Invasions invariably favor the defenders.


I should point the obvious fact that after war started at Europe in 1939 , most of Allied attention , resources , know how and best commanders were concentrated in there in European and Atlantic Theaters and Mediterranean Middle East Theaters. Especially after Fall of Low Countries and Fall of France in May-June 1940 which changed global strategic picture in a n unrecognasible or unfathomable level a few months ago. It complately made European colonial possesions in Asia and South East Asia either cut off from their homeland (like Dutch East Indies when Netherlands were invaded and occupied by Germans in May 1940) or weakened in defense since best British and Australian , New Zealand , Indian divisions and almost entire Royal Navy and RAF assets were diverted either to Atlantic Theater , British Isles or Mediterranean , Africa , Middle East. That left South East Asia and Pacific theater naked , defenceless and ripe for a quick invasion for battle hardned and experienced Japanese Armed Forces which were operationally much more effective in short term ansd made some excellent intelligence and planning work for their operations before hand. At the other hand local Allied (British , Dutch and US ) commands like Malaya , Burma , Java , Borneo , Philippines , Hawaii etc were uncoordinated in strategic cooperation , became complacent with soft colonial life away from war in Europe , operationally ineffective (compared to Japanese) , led by second rate or downright bad commanders who underestimated Japanese military resourcefulness and due to lack of assets and manpower they kept weak garrisons just in key locations like harbours or main cities that could be easily bypassed by Japanese which had the strategic initiative whole time.


Politics maybe? The only challenge to the Japanese in the area was the US. And when you have 92% of the voters against actively joining the war, FDR chose to rather give up the Philippines … besides, the US was already making $$ out of the Rent-Lease deal…
The conspiracy theory says that the US knew about Pearl Harbor and let it happen, so then they had a valid reason to get into the war. Pearl Harbor was not the worst case scenario, it would be the first place to strike … all the Pacific Fleet, sitting ducks… once you decide to get into war with America, this is where you strike.
Also… Japan, like Hitler, always had the advantage of the first move, the element of surprise… after the bitter experience of WWI, no western nation wanted to get into another war…


“This is in many ways more impressive than anything Germany has managed to date.”

Let there be no mistake about Germany defeating the largest and best prepared army in the world and about 11 other armies, almost capturing their main goal, luckely failing…

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I certainly don’t accept the conspiracy theory regarding the Pearl Harbor attack. While the USA had broken Japan’s diplomatic code by Dec 1941, they hadn’t broken the Navy code yet. Also, if you knew the attack was imminent, you would still cancel leaves and put personnel on high alert, and the attack would still be a propaganda coup of outrage, but with the added bonus that fewer of your ships were sunk.

I also think that US chronic unpreparedness for war bit home worse with the U-boats in the Gulf of Mexico in 1942 than at Pearl Harbor.


FDR was committed to engage in this war, supporting the UK from the start but had to overcome the isolationists movement in his own country first. By imposing economic sanctions on Japan, he knew Japan would be forced to go and conquer territories for oil, rubber and food. Clever boy!

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When the Japanese launched their offensive in Dec 41 they faced three opponents: the British Empire; the Dutch Empire; and the US Empire.
Firstly I think none of the allies imagined the scope of operations the Japanese were planning. Also the change in nature of naval combat from big guns to airpower was not yet obvious.
The Dutch homeland was occupied by Germany and any resources the Dutch had were focussed on liberating the homeland.
So the Dutch forces in the far East were short of resources and had mostly older equipment. Regular forces were spread very thin and most troops were local militia. Eurofocus affected training. The Dutch hadn’t been combatants in WW1 so had no serious combat experience at the command level. The airforce was large but the newest aircraft were a generation behind.
The navy was better, but had no capital ships or carriers and was facing what was the best navy in the world at the time.
The British Empire was fighting a two front war defending the UK and fighting in the Middle East. The Royal Navy was focussed on the Atlantic convoys and the Mediterranean and understrength in carriers having lost three so far and only four new commissions, most recently in Oct 41. So the Kino Butai alone matched the carrier strength of the RN. Within the first few months of the Pacific war the RN had lost all it’s capital ships in the area and priorities meant they could not be replaced in the short term.
Equally land and air forces of the British Empire were focussed on the fighting in Europe and the Middle East. Britain’s best troops were focussed on the Middle East so the Far East had predominantly understrength, under-equipped, and undertrained units. British strategy had also failed to grasp the possibilities of jungle warfare and depended on the navy. The Far East commands were at the bottom of the list when equipment priorities were set so the RAF had very few modern aircraft and again training was an issue.
The US had a navy/air strategy with air forces deployed in the Philippines and the Pacific fleet at Hawaii. The strategy for the Philippines was a holding action until a fleet led reinforcement arrived. Unfortunately the both the forward naval and air fleets were crippled by the Japanese on the first morning and the land forces were not battle ready.
On the other side the Japanese had planned out in detail their surprise attack. They had trained for it and a significant proportion of their troops, particularly junior officers and NCOs, had battle experience from China.
They had innovative tactics, particular the mass deployment of carriers working together and using bicycles to carry loads in jungle terrain.
I also think you overstate the challenge Japan faced in naval landings in 1941/2. Every landing was not a potential Omaha; we are looking at huge coastlines, mostly lightly defended. If you look at the US/German casualty ratio at Omaha it was 2+/1; Iwo Jima was less than 2-1 and Okinawa was closer to 1-2 and that’s with several years of wartime to build defences.
Sea invasion may favour the defenders, but how many failed in WW2?
Japan in 1941 executed a single integrated battle plan that ran like clockwork against opponents that were not battle ready with command structures that were not fit for purpose. Just as on paper the German success in France seems miraculous; both Japan and Germany were battle ready forces with confident leaders facing unready forces with poor leadership. And luck favoured the good.
Japan reached it’s high watermark by May '42.
After all it took Japan six months to capture Burma in 41/42 and six months to lose it in 44/45.

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