Britain holds Singapore during World War 2, what happens after?

[Riain]

The Fall of Singapore occured on the day after Sumatra was invaded, the two are inextricably linked despite so many books etc treating them in separate articles or whatever. Indeed I wonder how the news of the failure of the navy to intercept the Sumatran invasion impacted on Percivals decision to surrender the next day.

 

[Look More Closely Later]

Let’s just say Britain had a competent general and held Singapore. What happens after? Will the Allies hold the Dutch East Indies? How screwed are the Japanese? What effects are there on colonialism post war?

Well: For a start the Imperial Japanese troops which took Singapore in the original timeline don't get to go anywhere else in theatre; it's been a while since I looked at the matter, but I think some of the troops from Singapore provided a 'second wave' to help finish Sumatra (where Imperial Japan only had territory in the main oil-area, until then) and to push the invasion of Burma further forward.
But my memory of some reading I did on the matter a while back may be faulty.

Edit:
Politically speaking, I think there was a confidence vote in the UK in February 1942 (and a vote of censure later in the year after the Germans broke the British North Africa army Ritchie had commanded and captured Tobruk); the Confidence Vote probably gets avoided if Singapore holds, or at least deferred until round about the equivalent original timeline Tobruk disaster hits the British.)

 

[yulzari]

Surely the defence of Burma would be both more plausible and useful than the defence of Malaya, DEI and Singapore? Especially given the resources to hand. It has implications for China as well as SE Asia and a POD would be secure land route/s with India and China.

 

[Killer in]

If Malaya is held then the Brits will make a killing off selling rubber to the US, this should at least soften the cost of the war in general. It also among other many other butterflies slows the development of synthetic substitutes.

 

[HJ Tulp]

I really don't see the Allies holding on to Sumatra once Singapore is gone. It's no Rabaul in the Rough that can be quickly expanded in time to fight off a determined IJA assault

This gives the Allies an opportunity to win time though. The OTL invasion of Southern Sumatra (Operation L) was done with less than 4,000 men. Sending a division to Sumatra instead of Singapore secures the approaches to Singapore as the Japanese need to find and assemble a (much) larger invasion force. They might have to wait until Singapore has fallen and the forces in Malaya are ready for the next push. OTL this was not until 28th of February (Operation T). This was at the same moment as the invasion of Java. The Japanese were adament that the invasion would not be launched without securing both flanks so that will be delayed until Sumatra is secure. In case the invasion happens and it's succesful the port of Oosthaven is available to evacuate Allied forces to Java. All this frustrates the Japanese timetable for it's offensives, even discounting any possible effect of OTL's Fall of Singapore.

Singapore is where the useful stuff like oil tanks and floating docks are that you need to run a modern war.

True. And all that usefull stuff was useless because it fell. We have already established that without Sumatra it was doomed anyway. So why no priority on securing that deus ex machina first?

What does Sumatra have in comparison?

Except that it's vital to Singapores survival? It was also the primary reason for the Japanese offensive in the first place! The Palembang oilfields were needed to fuel the Japanese war economy. Without the DEI oilfields (of which Palembang was the most important) the Japanese will eventually run out of oil and will not be able to run a modern war.

Will the Dutch even let the Allies set foot there before the Japanese DoW?

Because the UK refused to guarentee the territorial integrity of the Dutch East Indies the DEI in turn had to stay neutral so this was impossible. There is no reason why forces couldn't be send after the Dutch DoW on Japan though (Japan only declared war on the Netherlands more than a month later).