Operation FB took place as part of the Arctic Convoys of the Second World War. The operation consisted of independent sailings by unescorted merchant ships between Iceland and Murmansk. In late 1942, the Allies had taken the offensive against Germany but the dispatch of supplies to the USSR by convoy via the Arctic route was suspended, due to the demands of the Mediterranean campaign. Convoy PQ 19 was cancelled because the Home Fleet diverted ships to the Mediterranean for Operation Torch which would have had to be postponed for three weeks had ships been provided for PQ 19.

The Arctic convoys of World War II were oceangoing convoys which sailed from the United Kingdom, Iceland, and North America to northern ports in the Soviet Union – primarily Arkhangelsk (Archangel) and Murmansk in Russia. There were 78 convoys between August 1941 and May 1945, sailing via several seas of the Atlantic and Arctic oceans, with periods with no sailings during several months in 1942, and in the summers of 1943 and 1944.