Now that i think of it, the best way to get the japanese to surrender earlier is to have a better british defense in Malaya. Theres been a couple of tls that did that. The british holding malaya is surely possible, at least for several months longer than otl.
Actually, it's possible to hold it indefinitely. All you need is a more competent and agressive commander, another couple of experienced Brigades, and a few more anti-tank guns or M2A4/M3 Light tanks. All they need to do is bleed the IJA a bit more and hold out for another couple of weeks.
It also means the japanese oil supply from the dei is a lot less secure, and gives the allies better forward bases when they do go on the attack.
This, but more importantly, it keeps the IJN from trying to take Sumatra.
I would also say that you NEED a Doolittle raid, yes it accomplished very little apart from a propaganda coup but it gave the Japanese the impetus to choose the central pacific strategy, a row that had been echoing round the militarys halls of power for a while. This lead to Midway. Without that you would probably have the IJN head south.
Feh. The Doolittle stunt's over emphasized.
It's better for the IJN to head south, and be picked off piecemeal in the East Indies. At best, it expended sixteen B-25s that could've been used elsewhere. Like Java or New Guinea.
It would've been far better to have
Hornet and her escorts (or Task Force 11, freed up by
Hornet's earlier presence in the pacific) at Makassar Strait (which occurred during the preparations for the Dolittle raid,) or even seconded to ABDACOM at all.
Hell, having a carrier and some B-25s in the region in early February 1942 and Malaya/Singapore holding out till about that time would allow ABDACOM to not only launch a relief operation for Singapore if needed, but to counter pretty much every attempt by the IJN and IJA to land in the Malay archipelago, and on New Guinea.
That'd certainly light a fire under the IJN's ass, and get them to focus on figuring out a way to get rid of the USN Carrier Fleet, especially after the RN regains use of Singapore, and the Allies have a chance to get their shit together.
This'd lead to *Coral Sea and *Midway, but with an already bloodied IJN going into it.