Below we see the Madeira Islands highlighted, with the Azores ~ 600 miles to the northwest, and Portugal’s capitol ~ 600 miles to the northeast. The Madeira islands are thus about equal distance from either, and a WWII era aircraft with at least this range would be required to stage from the mainland to the Madeira, and on to the Azores. Leaving these islands in allied hands would be giving them a perfect base to stage aircraft out of to interdict resupply to an axis Azores.
The Madeira Islands
Published
Azores Invasion WWII 