Columbia subject headings:
Harvard subject headings:
Defensive (Military science)--Congresses.
Europe--Military relations--United States--Congresses.
North Atlantic Treaty Organization--History--Congresses.
North Atlantic Treaty Organization--Military policy--Congresses.
Security, International--Congresses
United States--Military relations--Europe--Congresses.
Princeton subject headings:
Defensive (Military science)--Congresses.
Europe--Military relations--United States--Congresses.
North Atlantic Treaty Organization--History--Congresses.
North Atlantic Treaty Organization--Military policy--Congresses.
Security, International--Congresses.
United States--Military relations--Europe--Congresses.