I actually enjoy it when the UK throws an IC in India. Not only will I be able to take it with Japan in T3 or T4 (with the help of an E. Indies IC, of course) but it also forces the UK player to build 3 units there for as long as they have it. Those 10-15 IPC’s spent their each turn take too much away from the Atlantic. Let the US focus on Japan and the UK can deal with Germany.
Japan cannot just simply match US naval units in the Pacific. After the third US turn I usually have 1 battleship, 2 loaded carriers, 2 destroyers and 2-3 subs off the coast of Alaska, with 3 bombers in Alaska and another 3 maybe 4 subs that I just built in WUS. If Japan kept all their navy at home then sure they can attack my fleet but at what cost, I’m rolling 5 at 4 or less with at least 6 fodder. Plus my bombers and subs will counterattack what’s left (likely no destroyers). The first 4 turns the US player must go all out in the Pacific to even come close to slowing down Japan. The last 4 games I’ve played with the allies this plan has worked.