Contest in World War II between Britain (and later the U.S.) and Germany for the control of Atlantic sea routes.
Initially the Anglo-French coalition drove German merchant shipping from the Atlantic, but with the fall of France in 1940, Britain was deprived of French naval support. The U.S. then assisted Britain with the lend-lease program. Early in 1942, the Axis began a large-scale submarine offensive against coastal shipping in U.S. waters, and German U-boats also operated in force along the South Atlantic ship lanes to India and the Middle East. Allied shipping losses were severe, but the Allies succeeded in tightening their blockade of Axis Europe and combating the Axis war on shipping. By mid-1943 the Allies had recovered control of the sea routes.