I’ve thought about this, but to be honest, it’s a better American strategy.
American or British forces can land in SPAIN in one move from an NB. If you add a NB to SPAIN then you can shuck back and forth every turn. Landing combined allied units.
The best part is, MOST of the now pro Axis neutrals, like in Africa or S.A. there is limited access too. And the axis still HAVE to go there, etc. Plus German loses the N.O. if you hit Sweden.
Even better because France has more then one territory touching spain, The axis has to clump to one side or the other, It’ terribly dificult to defend against, especially with british advancing ground and amphibous units, with american support. Italy is directly under threat almost immediately.
So what if the axis pick up a few inf in turkey, swe, and Switz, I don’t think it’s enough to warrant against the fact that america can dump on you in one move. thus, every turn.
Once Russia is in the war too, what are they going to do?
Certainly worth considering for either side.