Following on from the work of Lipset and Rokkan, the evolution of political party systems in Western Europe since 1945 has been analyzed through the study of changes in the system of cleavages, the role of electoral realignments, changes in the paradigms and notions of party renewal, and the party life cycle. Since the 1960s and in the context of a "Global Revolution," the appearance of two new party cleavages, man-nature and identity-cosmopolitanism, a post-nationalist/sovereignist political divide, and the decline of secular-Church and owner-worker cleavages together with the disappearance of the procommunist-anticommunist political cleavage have encouraged the emergence of green and radical right-wing xenophobic parties as well as change in other parties. We now have to envisage the potential emergence of a new antiliberal-globalizing cleavage.