WI: the Easter Sunday Raid is a success

[johnreiter]

in April 1942, Japan launched and attack on Ceylon, headquarters of the British Eastern Fleet, with carrier based aircraft similar to the attack on Pearl Harbor. The goal was to destroy or cripple most of the British Eastern Fleet. The pan failed because the British were tipped off by intelligence, and had already dispersed their fleet when the attack came.

But, what if Intelligence had dropped the ball? In this timeline, for whatever reason, the British are not warned in time and the Japanese attack on April 5th is as effective as the attack on Pearl was?

How would this change the events of the war after this point?

 

[sparky42]

in April 1942, Japan launched and attack on Ceylon, headquarters of the British Eastern Fleet, with carrier based aircraft similar to the attack on Pearl Harbor. The goal was to destroy or cripple most of the British Eastern Fleet. The pan failed because the British were tipped off by intelligence, and had already dispersed their fleet when the attack came.

But, what if Intelligence had dropped the ball? In this timeline, for whatever reason, the British are not warned in time and the Japanese attack on April 5th is as effective as the attack on Pearl was?

How would this change the events of the war after this point?

Given how relatively little "major" operations happened after that raid, I wouldn't say huge changes, the RN was on the defence afterwards anyway, and Japan is still going to have to pivot back to deal with the USN. Perhaps some of the actions following in the Pacific have minor alterations due to losses the Japanese might have taken? Invading Madagascar might be altered depending on what hulls are left?

 

[Cryhavoc101]

in April 1942, Japan launched and attack on Ceylon, headquarters of the British Eastern Fleet, with carrier based aircraft similar to the attack on Pearl Harbor. The goal was to destroy or cripple most of the British Eastern Fleet. The pan failed because the British were tipped off by intelligence, and had already dispersed their fleet when the attack came.

But, what if Intelligence had dropped the ball? In this timeline, for whatever reason, the British are not warned in time and the Japanese attack on April 5th is as effective as the attack on Pearl was?

How would this change the events of the war after this point?

Little better than OTL to be honest as the British fleet was not based at Ceylon

It had created a super top secret base called Port T at Addu Atol 600 NMs south of Ceylon

In fact if the British had not been aware that the IJN were approaching then things might go better for them

OTL the British thought the Japanese were going to attack on or about 1st April and sortied / prepared accordingly with the British fleet attempting to do to teh Japanese what the USN did manage to do at Midway

Nothing happened, for various reasons the Japanese were delayed so everyone stood down thinking that they were not coming or never were - the main fleet returned to Port T to refuel except for the 2 Heavy Crusiers and Hermes which split off and went to Ceylon to refuel and resume other duties

So had their been no intel on the raid then all 3 main RN ships that were sunk would almost certainly have still been with Summerville's fleet at Port T or elsewhere and almost certainly not caught by the Japanese air fleets.

 

[Sekhmet_D]

in April 1942, Japan launched and attack on Ceylon, headquarters of the British Eastern Fleet, with carrier based aircraft similar to the attack on Pearl Harbor. The goal was to destroy or cripple most of the British Eastern Fleet. The pan failed because the British were tipped off by intelligence, and had already dispersed their fleet when the attack came.

But, what if Intelligence had dropped the ball? In this timeline, for whatever reason, the British are not warned in time and the Japanese attack on April 5th is as effective as the attack on Pearl was?

How would this change the events of the war after this point?

The British not being warned in time is NOT the POD you're looking for.

The true POD here is the No 4 scout plane from Tone, which discovered Cornwall and Dorsetshire, continuing on its bearing for another hundred miles or so after that sighting - doing so would have resulted in its crew spotting Indomitable and Formidable, which were not very far from where the cruisers ended up being sunk.

Kido Butai's B5Ns were already poised in reseeve to launch immediately should any additional British capital ships be detected; they would likely have overwhelmed Somerville's carriers.

As it stood IOTL, No 4 turned back after finding the cruisers and the Japanese never so much as glimpsed Indomitable and Formidable.

 

[GuildedAgeNostalgia]

Would Indian ports be open to raids/attacks by the Japanese afterwards?

If so, how does this affect the hump and campaigns in Burma?