Lord West explores the Royal Navy's three battles between the wars: with a new department in Whitehall, with communists in Russia, and with the Navy's oldest foe - the Treasury. The First World War left Britain reeling, economically devastated and with massive social dislocation and a generation scarred, both physically and psychologically, by the conflict. The country was on the back foot, and the Royal Navy was, too. The Navy's formidable new capability - its air arm - was taken away and handed to the newly-formed RAF. Constant raids by the Treasury were initially rebuffed, but eventually took their toll. And a perception grew up that the pre-war arms race had caused the war, and that the Navy had caused the arms race, and there was little outrage when the size of the navy was fixed. But alongside these battles in Whitehall, in international negotiations, and for the hearts and minds of the British public, the Navy also had a proper war to fight. For almost a year after the end of the First World War, the Navy - together with other British and allied troops - fought a war in Russia against the 'Red Army' of the nascent Soviet Union. Largely forgotten today because the exhausted troops were eventually withdrawn, the war nevertheless gave Estonia its first taste of independence. Producer: Giles Edwards.