This complex, ambitious, and large book seeks to question,
reformulate, and enhance the scope (and methods) of inter-
national relations theories, particularly those formulated
within a realist framework. The authors question that frame-
work, the Westphalian model of putatively unitary nation-
states, quantitative methods of empirical investigation, and
the levels-of-analysis paradigm. The breadth of their critique
is extensive and, consequently, highly ambitious. Rather than
approach international relations as a system of unitary
nation-states inspired by realist principles, which is arguably
a partial and simplified portrayal of contemporary research,
the authors favor a complex system of "overlapping, layered,
and linked polities" that have both horizontal and vertical
dimensions. The latter dimension is particularly important, as
it concerns patterns of authority, identity (including ethnic-
ity), and institutions that compete for the loyalty of individ-
uals.