Columbia subject headings:
Harvard subject headings:
Europe--Foreign relations--1918-1945.
Europe--Foreign relations--1945-
Europe--Foreign relations--19th century.
Europe--History, Military--19th century.
Europe--History, Military--20th century.
Europe--Military policy.
Princeton subject headings:
Europe--Foreign relations--1918-1945.
Europe--Foreign relations--1945-
Europe--Foreign relations--19th century.
Europe--History, Military--19th century.
Europe--History, Military--20th century.
Europe--Military policy.