Allied merchant shipping threatened by Japanse according to the U.S. Joint Intelligence Committee. Daily summary dated 22 December 1941

An item referred to ALUSNA Singapore reporting that the danger for merchant ships was growing which affected the routing of American ships. England sent all her merchant ships alway and transported all rubber and tin to Colombo,Ceylon.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 12 dated 22 December 1941.