George Ritzer Encyclopedia of social theory Vol 2 2004[1], Social theory has approached nationalism most as a political
ideology structuring relations of power and conflict. It has
focused on nationalism’s relationship to ethnic violence
and war, on the production of beliefs that one’s own country
is the best, and on the invocation of national unity to override
internal differences. It has seen nationalism first
through bellicose international relations and second
through projects by which elites attempt to mobilize mass
support. This has been an influential view both among
scholars of nationalism (such as Michael Hechter) and
among general social theorists (such as Jürgen Habermas)
who have tended to see nationalism largely as a problem to
be overcome.
A second strain of social theory, associated with
modernization theory, as anticipated by both Weber and
Durkheim has seen nation-building as a crucial component
of developing an effective modern society, one capable of
political stability and economic development. Nationalism,
as the ideology associated with such nation building is thus
important to a phase in the process of becoming modern
and also a normal reflection of industrialization and state
formation. Ernst Gellner, Charles Tilly, and Michael Mann
are key representatives. But however normal for a developmental
phase nationalism may be, all see it as also deeply
implicated in power relations and conflict.