Its not game over for the Allies, but taking India out of the picture means Egypt is going to be much easier for Germany to take for Europe’s win. Leaving India around and particularly if not threatened generally means Cairo is going to be a tough nut to crack for the Axis.
Everything else is very subjective and situational because the Pacific is so big and the US can simply spend rounds 1 and 2 in the Pacific and can cause some serious problems for a Japan that has not removed any US starting navy.
That’s a very good statement here.
I want to say, however, that you do not need to capture India to ensure a fall of Cairo.Putting a submarine there to reduce UK-PAC income to <=3 is sufficient more often than not. As long as you make sure, that you’ll always be able to move a couple of transports in range for an India invasion, the Indian forces can’t move to Cairo. As soon as they start moving, just put the transporters to FIC or Malaya again, and UK-Pac will have to retreat to defend Calcutta.
There is truth in this statement. Containing Calcutta is more important than conquering it. There is a cost associated with allowing India to persist such as maintaining a convoy which requires shutting the economy down outside of India whilst protecting SS that can be threatened simply by UK putting a DD off S.Africa which will be difficult for Japan to block. Sydney can also sneak DD around to remove the convoy. Blocking both routes to lift the convoy costs resources Japan would much rather have threatening the VC win at either Hawaii or Sydney.
Alternatively you have to basically go “All-In” to take out India as Japan which may or may not include sacrificing a significant portion of the air force to do so. An Air force that generally creates a massive advantage in the naval battle because Japan can spend 16 IPC to place a Carrier and load it with 2 Aircraft whereas the US must spend 36 IPC to maintain the equity of naval presence. Japan will happily trade its surplus in aircraft to sink US carriers, and BB. Of course the inherent weakness of a heavy Japanese Carrier build are US bulk builds of submarines which nullifies the air superiority of Japan once Japan has to decide between losing the screening Destroyers (to hit the subs with aircraft) or aircraft to get another round to hopefully wipe out the subs before Japan’s carriers are unable to let aircraft land on them.
As it is with the common cold, it would be infinitely better to cure the common cold than treat it as treating it leeches resources better used elsewhere. The problem is curing things is easier said than done.
In the case of Japan, removing Calcutta is infinitely more valuable than simply convoying it. Convoying, however, is a good alternative if India plays well and creates an expense battle for Japan.