From: Little England
If this game were modeled on real life, there would be several ways to bring Japan to its knees: (1) Air War: Destroy Japan's ability to defend itself, eventually allowing nearly uncontested attacks on the Home Islands; (2) War at Sea: Destroy Japan's navy, thus allowing the Allies to close on Japan proper and impose a blockade; (3) Ground War: Destroy Japan's army so that it cannot defend itself; and (4) Economy: Destroy Japan's economy, thus negating the other three. Each of these is interrelated, of course, so that the Allies will be actually workign on all four, but as the game develops, a player will often begin to focus on one or two as he begins to experience some success.
In AE, the third option (Ground War) really isn't available. Japan's army is too big. The first isn't an option either, which comes as a surprise since the air war was such a decisvie Allied victory. The Allies can win the air war in AE, but they can't destroy Japan's air force. Oh, there might be one game in a hundred in which an elite Allied player might bring Japan to its knees, but those will be very few. GJ has simply eaten - and continues to eat - Japan's airforce in this game, but the airforce is still there in huge numbers causing major problems.
That leaves combat ships and the economy as Japan's weak points. Destroying an economy will take time, unless Japan self destructs, but the navy is another matter. That is a finite resource that can be destroyed.
(1) I would argue is only true due to the house rules in effect in Greyjoys game. He has been completely hamstrung IMHO, for his own enjoyment at that as he wants an interesting and hard fight rather than a rubblebouncing exercise. Really if I was him, free of house rules, I'd be night bombing Japan from 8000 feet with everything I've got, which Greyjoy is not allowed to do due to house rules. In fact you can see rader on the tech support forum arguing that if Greyjoy did this Japan would be down for the count in a few months. Somewhat over the top I think but... give it six or nine months not a few, and it would work.
(2) Definitely the weak point IMO so agree there. Sunk ships dont come back.
(3) Broadly agree here. Depends if China is in the fray. I think with an Allied Burma and a supplied China it may be possible, but the IJA is enormous, so I think until the USSR gets involved the IJA is probably too big. But I've seen AARs where China goes on a rampage and has the IJA being pushed back so seems to be in theory possible if that happens.
(4) From what I've heard from experts at Factory Manager in the Pacific, it seems not even Palembang is all that important. Thats why I hope from my PoV that your game continues. You supposedly have Japan by the throat in this game. I'm curious what that actually means. The assertion that Japan is toast without oil is well known and I dont really disagree but I'm very curious how long Japan can keep kicking before total shutdown. I'm inclined to think that with someone good at optimising their economy and doing ruthless management, like cutting all shipbuilding for example say, you would find that Japan can keep on kicking for a hell of a lot longer than anybody might anticipate.