Between Preventive Attack and Collaboration: British Military Planning on Spain, 1940–1944

In the early stages of the Second World War, Spanish dictator Francisco Franco and key regime figures were tempted to enter the war on the Axis side. This temptation was a serious concern for British wartime strategy. This article studies the British military operations prepared to confront the possibility of Spain entering the war between 1940 and 1944. These operations aimed to protect Gibraltar, maintain access through the Strait of Gibraltar, and reduce the Axis threat to maritime communications in the eastern Atlantic. The article sheds new light on three issues: the balance of advantages and disadvantages that the plans entailed and the preparations to carry them out; the simultaneity of planned operations to cooperate with the Spanish Armed Forces and ones to confront them; and the importance of Spanish non-belligerence as a differential factor with respect to other neutral European countries.