An analysis of a major World War II air interdiction campaign which was designed to force the withdrawal of the German armies from central Italy by denying them essential supplies. As it turned out, Operation STRANGLE had less effect on the enemy's supply problem than had been expected but made a major contribution to the Allied victory in a way that had not been generally foreseen. The interdiction campaign succeeded in paralyzing the tactical mobility of the German armies during the combined Allied ground and air assault on the heavily fortified enemy positions. The study raises questions that may have an important bearing on the future use of tactical airpower and the doctrine for its employment. Why did supply denial prove unattainable in Italy, and should mobility denial have been chosen as a preferred objective? Bibliography includes both Allied and German accounts of the campaign.