Columbia subject headings:
Harvard subject headings:
Great Britain--Foreign relations--Portugal.
Great Britain--Foreign relations--Spain.
Islands of the Atlantic--History--20th century.
Portugal--Foreign relations--Great Britain.
Spain--Foreign relations--Great Britain
World War, 1939-1945--Diplomatic history.
Princeton subject headings:
World War, 1939-1945--Atlantic Ocean.
World War, 1939-1945--Naval operations, British.