Realism
Raymond Aron
Edward Hallet Carr
Robert Gilpin
John Herz
Samuel Huntington
George Kennan
Stephen Krasner
Hans Morgenthau
Kenneth Waltz
Liberalism
Karl W. Deutsch
Michael Doyle
Francis Fukuyama
Ernst Haas
Stanley Hoffmann
Robert O. Keohane
Richard Rosecrance
Constructivism
Friedrich Kratochwil
Nicholas Onuf
Christian Reus-Smit
John Gerard Ruggie
Alexander Wendt
Critical Theory
Robert Cox
André Gunder Frank
Stephen Gill
Antonio Gramsci
Jürgen Habermas
Andrew Linklater
English School
Hedley Bull
Barry Buzan
Timothy Dunne
John Vincent
Martin Wight
Postmodernism
Richard Ashley
David Campbell
Michel Foucault
Robert B.J. Walker
Feminism
Jean Bethke Elshtain
Cynthia Enloe
Christine Sylvester
J. Ann Tickner
International Political Theory/International Ethics
Charles Beitz
David Held
Terry Nardin
John Rawls
Michael Walzer
Historical Sociology
Anthony Giddens
Michael Mann
Justin Rosenberg
Charles Tilly
Immanuel Wallerstein
Source: FIFTY KEY THINKERS IN INTERNATIONAL RELATIONS – Martin Griffiths, Steven C. Roach and M. Scott Solomon