21 Msg, Marshall to McNarney, 14 Apr 42, CM-IN 3714. The British Chiefs stated the consequences of Japanese control of the western Indian Ocean as follows: (1) the Allies would be unable to support forces in the Middle East, and the Germans would gain access to oil and other resources of the area, and the Far East; (2) the loss of oil supplies from Abadan would be irreparable; (3) the southern supply route to the Soviet Union would be cut; and (4) Turkey would fall an easy prey to the Germans, and German naval forces would be able to enter the Black Sea and turn the Soviet position in the Caucasus.