I have received your message of March 30 advising me that you and Mr Roosevelt are compelled by necessity to postpone despatch of the convoys to the U.S.S.R. till September. I regard this unexpected step as a catastrophic cut in the delivery of strategic raw materials and munitions to the Soviet Union by Great Britain and the U.S.A., because the Pacific route is limited in shipping and none too reliable, and the southern route has small clearance capacity, which means that those two routes cannot make up for the cessation of deliveries by the northern route. It goes without saying that this circumstance cannot but affect the position of the Soviet troops.