Japan declares war on France over Indochina in 1940

Launching an invasion is one thing, maintaining it is another, and the Japanese in 1941 maintained their operation from Indochina.
I don't doubt that the invasion of Malaya would be delayed until after the conquest of Indochina. Nor that Japan in OTL would use closer bases to support an invasion. Regardless this doesn't mean a Blitzkrieg is impossible anymore than Japan not acquiring Borneo prior to the war meant they couldn't Blitzkrieg OTL.

If the supply dumbs are initially located in Hainan then it's a significantly longer journey but as we know from OTL Japan did not need to use their wartime supply routes for long because they conquered Malaya in 2 months and could move supply dumps to Thailand almost immediately after the war starts.

Particularly as this is before the Franco-Thai war in December 1940.

I don't think it is so easy to say that a war in July 1940 against only European powers (if Britain even intervenes) is worse for Japan than a war in Dec 1941 against EU + USA. There are downsides and upsides.

In addition paint a map of the world in the Axis in July 1940. The UK seems to stand alone against the whole Eurasian Continent, remember no one knew about Barbarossa. This will be a major hit for British morale. France falls in days and you're at war with yet another Great Power?
 
Last edited:
IIRC the British government had already signalled that it would not (or better said: could not) intervene in case of an opposed Japanese invasion of Indochina. This was one of the reasons for the French surrender. So no general war but a campaign limited in time. It is going to cost Japan men and material to conquer the colony but the French forces and administration was pretty demoralized. Are there any benefits to the Japanese? Maybe Siam joins the Japanese camp earlier and more decisively as the British position is shown to be weak and the Japanese give them Cambodia or something like that? Would the lack of an Vichy-Japanese 'alliance' in Japan make Ho Chi Minh susceptible to collaboration?
 
An interesting consideration:

OTL Japan didn't want to be saddled with the administration of Indochina and largely left that the the Vichy authorities, and then to some native collaborators after it determined that the French couldn't be trusted. In a TL where Vichy declares war there isn't going to be Vichy authorities to collaborate with, and the Japanese have yet to sus out which locals can be trusted to collaborate.

So, what if the Japanese offered to return the colony to Free French administration in exchange for basing rights and the allies ending arms shipments to China? What would London say to that?
 
IIRC the British government had already signalled that it would not (or better said: could not) intervene in case of an opposed Japanese invasion of Indochina. This was one of the reasons for the French surrender. So no general war but a campaign limited in time. It is going to cost Japan men and material to conquer the colony but the French forces and administration was pretty demoralized. Are there any benefits to the Japanese? Maybe Siam joins the Japanese camp earlier and more decisively as the British position is shown to be weak and the Japanese give them Cambodia or something like that? Would the lack of an Vichy-Japanese 'alliance' in Japan make Ho Chi Minh susceptible to collaboration?
It’s possible for the British to hold in the Far East like they did OTL. It will hurt the British baldly but it will not defeat the British.
 
It’s possible for the British to hold in the Far East like they did OTL. It will hurt the British baldly but it will not defeat the British.
Sorry but I don't understand what you are saying :)

Do you mean that you think that the British would intervene in a conflict between Vichy France and Japan and be successful?
 
An interesting consideration:

OTL Japan didn't want to be saddled with the administration of Indochina and largely left that the the Vichy authorities, and then to some native collaborators after it determined that the French couldn't be trusted. In a TL where Vichy declares war there isn't going to be Vichy authorities to collaborate with, and the Japanese have yet to sus out which locals can be trusted to collaborate.

So, what if the Japanese offered to return the colony to Free French administration in exchange for basing rights and the allies ending arms shipments to China? What would London say to that?
What arms shipments. The allies which is just Britain have no spare arms
 
Sorry but I don't understand what you are saying :)

Do you mean that you think that the British would intervene in a conflict between Vichy France and Japan and be successful?
Not unless they were suicidal, which they weren't. Britain has much larger problems than Japan invading Indochina very close to home, and in the Autumn of 1940 absolutely nothing to spare for mad adventures in the Far East.
 
Sorry but I don't understand what you are saying :)

Do you mean that you think that the British would intervene in a conflict between Vichy France and Japan and be successful?
What I mean is the British will be able to hold their position. OTL the British retreated from Burma to India where it’s easier to defend.
 
Not unless they were suicidal, which they weren't. Britain has much larger problems than Japan invading Indochina very close to home, and in the Autumn of 1940 absolutely nothing to spare for mad adventures in the Far East.
What happens to Britain then? Vichy and Free France? Germany?
 
What happens to Britain then? Vichy and Free France? Germany?
Britain's position is no different to OTL. At the moment unless Britain does something stupid Japan has no need to move against them or the Dutch, it was American actions that triggered that as part of their war against the US. Japan won't be and can't be ready to attack the US (and the British and Dutch) until late 1941. Britain might divert some of the equipment they sent to the Soviets to Malaya due to the Japanese threat being a bit more obvious but I doubt it.
 
Britain's position is no different to OTL. At the moment unless Britain does something stupid Japan has no need to move against them or the Dutch, it was American actions that triggered that as part of their war against the US. Japan won't be and can't be ready to attack the US (and the British and Dutch) until late 1941. Britain might divert some of the equipment they sent to the Soviets to Malaya due to the Japanese threat being a bit more obvious but I doubt it.
Britain being more prepared might do better in Malaya when the war with Japan does happen. They might even hold Singapore.
 
I know that but that is not 1940. That page says in OTL Britain closed the road in July 1940 at Japan's request so no arms is definite
*for three months. As in they were resuming shortly after the ultimatum to France.

Anyway the issue is what to send not how
Britain was transhipping war materials from America, which had been allowing China to buy war materials on credit so long as a third party shipped them over.
 
Below I will post the parts of Bussemakers Paradise in Peril that I think are relevant to the discussion. I copied it from the pdf in this link https://pure.uva.nl/ws/files/3097492/11106_UBA002000496_15.pdf which causes some errors.

'Almost all colonial governments declared their support to Maréchal Pétain,, including Governor-General Catroux, although he was rather pro-British (See below).. This was a disappointment for the British, who had hoped that Catroux would line upp with De Gaulle, setting an example of courage to other influential French colonial governors.24933 The British government considered it unwise however to extend a British guaranteee towards FIC; the only measure which would have kept the French in Indochina on thee allied side.'

'On 28 June 1940 in the afternoon Governor-Generall Catroux and Vice-Admiral Decoux had a last discussion with Sir Percy Noblee on board the French light cruiser LAMOTTE PICQUET in Saigon. Afterwards Noble discussedd the results of this meeting with the Dutch Consul-General in Singapore, who dulyy reported the contents of the conversation.2495 Accordingg to Noble, both Catroux and Decoux declared themselves to be on the English side,, but they asked for the support of the Royal Navy in case of a Japanese action againstt FIC. General Martin, also present, asserted that in the event of a Japanese attack thee French "would fight to the last soldier". Noble informed the French flag officers that Greatt Britain would withdraw its naval forces from Hongkong and concentrate on Singapore,, therefore leaving the South China Sea to the Japanese. Moreover, to compensate for thee naval losses, he had to send units of his fleet to Western Europe, including all his submarines.. He could not promise air support either, as he informed the French commanders that the British had too few planes even to assure the defence of Singapore.2 " 8 Nevertheless,, Noble tried to convince the French that in the long run FIC would be better off if the French sided openly with the British, and distanced themselves from Pétain. The G.G.. declined such a move, pointing out that it would mean a change in the status quo of 19222 (the Washington Treaties) and therefore would induce Japan to attack. Decoux informedd Noble that the French Navy would remain loyal to the legal government of France.2 * 77 As a consequence, he turned down the offer of Noble to have the French squadronn based at Singapore. Such a move would have exposed the FiC coast to the Japanesee Navy, and therefore made no sense.24"

'Accordingg to Hesse d'Alzon,2800 the evident weakness of British forces in the Far East wass the main reason that France had no other choice than to seek an accomodation with thee Japanese, as their naval and air forces were insufficient to withstand a determined Japanesee assault It leaves open the question as to what would have been the French position,, if England had bluffed and had assured the wavering French of British naval and militaryy support Catroux might well have been able to secure FIC for the Free French Movementt of De Gaulle. But the British themselves, reeling from the defeat in Flanders hadd no coherent Far Eastern policy at that time. (See Chapter 2). Therefore, in order not to o upsett the apple cart, the British took no risks in giving the Japanese an excuse for occupyingg FIC. Gaullist broadcasts from Singapore were even halted.'

'Thee British did not help by enforcing a blockade of French shipping all over the world whichh isolated the colony even further, excepting only traffic over the South China Sea, whichh was covered by the Gentlemen's Agreement between Noble and Decoux. The Frenchh freighter ESPERANCE was even brought up on its way from Madagaskar to Djibouti,, were it was scheduled to transport 4 battalions of Senegalese troops to FIC2505 . Thee French Government then ordered all French vessels into French-controlled harbors, againn with the exception of FIC itself. An understanding was reached, however, and from 5 Septemberr 1940 one ship each ten days was allowed to depart from Marseilles to FIC. Thiss line of communication remained open until September 1941. The British however did nott allow any substantial reinforcement of FIC for reasons which will be explained below. Thee French used the opportunity to ship as much German and Central European members off the Foreign Legion from France and North Africa to FIC, in order to keep them out of Germann hands.2506 In FIC they rejoined the 5e R.E.I. (See sub-chapter 5.3.3.1 below). '

'British sources (including Tarling) have not given an explication, why the British did not alloww French weapons and troops destined for FIC to be transported to FIC. A strong Frenchh defence would have made a Japanese take-over of FIC more difficult, thereby gainingg time for the British. It was implied by the French government, and also reported by the American Ambassador (Murphy) at Vichy to the State Department, that the English governmentt did not risk a conflict with Thailand by allowing the French to reinforce FIC2507 .. Murphy had a discussion on this subject with Jean Chauvel (Chief of the Far Easternn Section of the French F.O.), in which Chauvel accused the British of assisting in Thaii aggression against FIC by withholding French reinforcements.2508 There may be moree than a kernel of truth in these allegations, as the relations between Thailand and Greatt Britain always had been very cordial in the past. It was a welt-known fear of the Britishh military that by occupying Thailand the Japanese would be enabled to march to Singapore through the back door of Siamese Malaya'

'Next to the Senegalese battalions, the French had 90 modern planes shipped from the U.S.A.. and intended for France, on board the French aircraft carrier FRS BÉARN. After the armistice,, the ship was holed up at Martinique however, and not allowed by the British to proceedd any further. Early in September 1940, the British blockade of Martinique was lifted,, but then the French Government interpreted the Armistice conditions with Germany ass not allowing the use of these planes to reinforce FIC. The American government was well-informedd however, and as the Americans were unwilling to ship weapons to FIC, becausee they expected those weapons to fall into Japanese hands anyway'.

'The British Government understood that the only way that FIC could be saved for the Free Frenchh movement then establishing itself in London under De Gaulle, would be by guaranteeingg French sovereignty over FIC.25" This the British were unwilling to do, becausee the Japanese might interpret such a move as a change in the status quo, leading too war with Japan. In those hectic and fateful days just before the Battle of Britain, the Britishh government could not possibly give such guarantees. But the British were willing to give diplomatic and economic support to keep Indochina at least French, even if it would mean the support of a colonial régime instructed by Vichy-France.'

'Lord Lothian declared that the UK was willing to give some military assistance too the French in order to avoid Japanese occupation, but he insisted on American support. Hulll stated that it was not the policy of the U.S. to support a colonial government against aggression,, when its motherland was unable to give military support. This applied to both Francee and The Netherlands.'

'Thee ink of the signatures was not yet dry, when the Japanese Southern Army attacked the Frenchh border posts in the evening of 22 September, as its commander and staff disagreedd with the agreement signed that day in Hanoi. The military events of what was the first dashh between European ground-based troops and the Japanese Imperial Army in the Secondd World War has been described in more detail in subchapter 5.5.2. After a few dayss of fighting, the French lost Langson, and Generals Buhrer and Martin had been put to shamee for their over-optimistic estimate of French military superiority over the Japanese in actuall combat The French over-estimation of their fighting prowess over the Japanese provedd to be an embarrassment even to the French diplomatic missions in the Far East29611 According to this source, the French colony had maintained unreasonably high expectationss about its defence capacities for years; expectations which had been brought downn to earth due to the Langson debacle. '
It is evident that the British government wasn't going to help the FIC to repel a Japanese invasion in any substantial way. Not without US assistance anyway.
 
Top