Thanks for the game. as you said, the first nail in the coffin was the Yunnan attack. Japan has to achieve something major when making such a sacrifice. This was not the case. India was still rather strong and the Chinese weren’t dead. Still had their fighter and even artillery. Russia could recover, too.
And as you said, the final nail was the US taking Norway because this allowed infinite fighter support for Moscow.
You might have had an attack at Moscow without Norway but I would have found ways to bring a bunch of fighters in anyway. Thus I think Axis would have needed huge dice at a Moscow attack, otherwise Germans would not have managed to go further after Moscow, especially as Japan was falling apart.
Good luck in your other games and thanks again for the game. You are a kind and nice opponent and a great sportsman.