Ideology and international relations

What is the relationship between ideology and international relations (IR)? The extant literature focuses on how the former shapes the latter. Confrontation between Liberalism and Fascism, Communism, and Authoritarianism have sequentially structured IR over the past Century. While such all-encompassing Ideologies may unify the people of different nations in (often opposing) worldviews, liberal/left and conservative/right ideologies can divide...