When the German Army invaded USSR on 21 June 1941, the Soviet authorities were taken completely by surprise. At a stroke the European diplomatic situation was transformed, and Britain, hitherto standing alone against Hitler, found herself with an ally of huge potential.
For the six years between 1939 and 1945, Naval action was seen on every ocean of the world.
No conclusions, perhaps, are stronger than that in attack and in defence the navies of today have forget theirprincipal weapon in the air; that the exercise of sea power.
The book tells the story of the British Submarine Service in two savage and bitter wars foufht beneath the seas.
During the Scond World War the major Navies, with the most potent weapons ofwar development in the twentieth century