The Portuguese in WWII

The problem from Hitler's perspective is whether or not invading Spain first to get at Portugal is acceptable. That's going to tie down 20+ German divisions indefinitely, hand valuable island bases to the British and inflict a real blow to relations with neutrals and even other fascist regimes(such as Italy).

It may be that a Portuguese brigade or so and British bases in the Azores may have to be swallowed.

Then again, Hitler is not always known for his calm, detatched, rational decision-making process. It also bears mentioning that Portugal and Spain would both have useful naval bases for the Battle of the Atlantic, and if Gibraltar can be taken Britain's position in the Mediterranean is going to be more troubled than OTL.
 
Yet the UK benefits by gaining the Spanish and Portuguese Islands in the Atlantic, and most/all of the Spanish and Portuguese colonies, while Germany has to consider how long the campaign will take, how many units will be required to take both countries, how neutrals and even friendly countries will respond and, most importantly, to hold Spain and Portugal and prevent any British landings how many divisions will be required for garrison purposes and therefore not available for Barbarossa?

A rather modest 20 divisions means Barbarossa reduced by 10%.
 
Top