To his surprise the letter aroused the interest of the Special Operations branch of the OSS, responsible, among other things, for sabotage. Hall was ordered to report to Washington. He received his initial training in the US and was then sent to Algiers, North Africa, as a demolitions expert. A mission directly against the Brenner Pass was seen as unrealistic, partly because local partisan support seemed unlikely given that the inhabitants of the region of South Tyrol, also part of Italy, were predominantly ethnic Germans.