If formal organization provides a narrow view of international organization, the
most expansive definitions of international organization are framed in terms of
broad ordering principles of the international system. We focus on two here: the
realist conception of self-help in anarchy and the English school view of
‘society’. We do not consider other ordering principles such as Marxist theories
of imperialism (Lenin, [1917] 1939) or of a ‘world capitalist system’
(Wallerstein, 1979), although the economic logic they describe certainly
constitutes an alternative international ordering principle. The two we do
consider play a central role in debates regarding the nature of international
organization and pose major alternatives to regime theory which we consider
below.