I now think a similar idea could apply to Finland.
Its 4 infantry can only move in the following territories:
Finland
Vyborg
Karelia
Norway
Sweden (not if the Axis are at war with the strict neutrals)
Back in Early 2023, Dark Knight and I had a game, where I was playing the Allies - and gradually preparing the USA for an invasion of the Home Island of Japan.
This picture shows the situation in Late 1944 and clearly demonstrates why it is extremely difficult to invade Japan when you play against a Highly Skilled Opponent:
An Allied Economic Victory was achieved before the invasion of Japan took place.