Before 1940, Germany's modest submarine force was expected to pass through constrained northern approaches while France remained an active ally and Norway stayed neutral. A war with Japan suggested aircraft ferrying to the Far East more strongly than Atlantic convoy aviation, while an Italian war could be contained within the Mediterranean. These were logical plans based on recent experience, not simple ignorance of naval aviation. The urgent escort-carrier requirement appeared when France fell, Norway was occupied, and German forces gained direct access to the Atlantic.
Chapter · 33:28-36:07
Reasonable assumptions hide the escort-carrier requirement
Prewar planners expected France to remain in the fight, Norway to stay available or neutral, and distant wars against Italy or Japan to create different carrier needs.