That's why Germany and Japan should start hunting for resources (seek other means of fabricating it, develop less resource-demanding designs, etc.). Money will become no problem due to the whole "we are at war, we must win at all cost" (something like unlimited credit until the war ends, and in this game end of war means end of the game).
This pinpoints the underlying problem in almost all discussions of money in HOI. There are essentially two very different things being discussed when talking about money.
There is currency, as in what is used to pay wages and buy things from other nations. This is where the concept of national debt and debt forgiveness comes into play. This is the historical, real world, sense of money. I am sure this is the sense in which you are using it.
I, and some others, are using money in the sense of it's applications within the game. There are some parts to the economy that are not going to work well without some form of money. It is meant strictly as a game mechanic used either to facilitate trade or represent allocation of limited internal resources of some sort. At no point does this concept of game money have to tie into real world currency in any way. This concept does not have to allow for debt etc.