I believe that I failed to make myself clear in my original post, in regards to the basing of the US Asiatic Fleet in Singapore. I wasn't suggesting that this took place, at anytime other than after the British had successfully held a major portion of Malaysia and Singapore, and the Americans had been forced out of the Northern Philippines. At such time, the question becomes where to base the remnants of the US Asiatic Fleet. The options are limited, the Southern Philippines, the DEI, Australia or Singapore. Both the Southern Philippines and DEI, suffer from there lack of a modern developed port. Australia has such a port Sydney, but it is a long way away, and doesn't yet have a large dry dock. Singapore has one of the largest dry docks in the world, and a fully equipped military shipyard. But before considering the whys and wherefores, of basing USN ships in Singapore, let's look at the state of play.
Germany, having failed to knock Britain out of the conflict, failed to capture Malta, Crete or North Africa, has invaded the Soviet Union, where it is doing much better than it did IOTL. And this strangely could be of great benefit to the British. Hitters obsession with destroying communism, along with his inability to remain focused on the big picture. Will cause him to put to one side the problems in the Mediterranean theatre, and concentrate all German efforts against the Soviets. His rationale being that once he has destroyed the Soviets, he will be in such a superior position that his other problems can easily be dealt with. Resources that should be deployed in the Mediterranean, will instead be sent to the Soviet Union, making the British task easier.
The British are in a much better position ITTL, than they were in OTL, and thus better able to respond to the rising threat in the Far East. The Western Desert campaign is going very much to the pre war planning. The British initially made a tactical withdrawal, bleeding the Italians in the process, and stretching their logistics train in the process. They then counter attacked and have driven the Italians back beyond their initial starting point. Which has made the resupply of Malta far easier, and reduced the strain on British logistics. The campaign in East Africa, has gone well, which has also helped British logistics. The loss of Greece while embarrassing, hasn't been a complete disaster, and retaining Crete, has reduced RN losses in comparison to OTL, while enabling Britain to retain control of the Eastern Mediterranean. Not having to run major convoys into Malta, and it's retention as a major source of interception forces against the German and Italian resupply convoys, is increasingly reducing their ability to fight in North Africa.
Britain's better performance in the Mediterranean, is allowing her to reinforce the Far East to a greater extent than she was able to IOTL. Given how close the Japanese were to losing their campaign in Malaysia IOTL, it is highly likely that they will fail in their efforts ITTL Other than forgoing their campaign against the Americans, they can not release sufficient resources to win against the British.
The RN having suffered significant less losses than it did IOTL, especially in the Mediterranean, should be able to provide a more balanced fleet for the Far East. So roll the dice, if it's a six, thats two modern KGV BB's, and two BC's, with two AC's in support, plus assorted, CC's, CL's, DD's, etc. If it's a one, then its only the forces that were sent IOTL, but even then, they stand more chance than they did. Montgomery for all his faults, was a very competent General, and one who had done a lot of thinking. Having served in India, he knew of the strengths and weaknesses of the Indian Army, and had in 1938 organised the first major inter service amphibious landing exercise, carried out by the British. He will not let the Japanese get inside his head, very little did, and will want to impose his will on the campaign. Odds are he will retreat onto prepared defensive works, hold in place until he feels the time is right, and then counterattack. Probably with a small amphibious hook behind the Japanese line, ether launched from Singapore or Northern Sumatra.
The failure of the Japanese to capture Singapore, protects Sumatra and provides a resupply route beyond Japanese interference into Singapore. It also provides areas for reserve airfields thus further dissipating Japanese efforts. No fall off Singapore, also makes any attack on Burma very difficult for the Japanese.
The Americans while in a slightly better position than they were IOTL, more ships and slightly better prepared. Still face the problem that the majority of Americans thought of the Japanese as short sighted, buck toothed, little yellow monkeys. And one Yank was worth twenty Japanese, and could beat them one hand tied behind his back. Depending on how the Japanese roll the dice, and how the Americans react, the opening stages could go as bad or a lot worse for the Americans. If the Japanese throw a series of sixes, you could see not only the battleships of the Pacific Fleet go down at Pearl, but the aircraft carriers too. It is going to take time for the Americans to wake up and smell the coffee, and get their act together. The fall of the Northern Philippines, leaves the American Asiatic Fleet with three choices, go south to the Southern Philippines or the DEI, both of which lack the infrastructure to support the fleet. Go east to Pearl, which is a very long way away from where they are meant to be. Or go west to BNB and Singapore, and stay in the fight, and in contact with the remaining troops on land.
Yes the Americans are going to want to be in complete control of the forces in the theatre, that goes without saying. But no matter how much King jumps up and down, or MacArthur throws his toys out of the prom. Singapore is Britain's principal military base in the Far East, and the British are not going to hand it's defence and control over to the Americans. Yes Britain is financially strapped, though not as badly as she was IOTL, but militarily she is in a much stronger position, and far less reliant on America. Winston is in a stronger political position both domestically and internationally, and until the Americans have a lot more boots on the ground, is going to be calling the tune.
Retain Burma, and you keep the Burma Road open, thus eliminating the need for the airlift into China to keep them active in the war. You also don't have the problems of a threat to India and having to set up a major defensive network on land, sea and air. You have also much reduced the possibility of a major famine in Bengal, and the problems this caused. Between Burma and Malaysia you have a number of important export commodities vital to the combined war effort. That can ether be sold for cash, or exchanged as part of reverse lend lease.
The butterflies wings are beginning to flap faster, and the divergence from OTL, is going to become more evident with every passing week.
RR.