Columbia subject headings:
Europe--History, Military--20th century--Congresses.
Imperialism--History--20th century--Congresses.
International relations--Congresses.
Nation-state--History--20th century--Congresses.
Security, International--Congresses.
United States--History, Military--20th century--Congresses.
Harvard subject headings:
Europe--History, Military--20th century--Congresses.
Imperialism--History--20th century--Congresses.
International relations--Congresses
Nation-state--History--20th century--Congresses.
North Atlantic Treaty Organization--Congresses.
Security, International--Congresses
United States--History, Military--20th century--Congresses.
Princeton subject headings: