It is very possible that the "Third World" never existed during the heyday of the ideology of Third-Worldism, for most of the "Third-World" nations in practice tilted to either the "East" or the "West." Perhaps the only authentically Third-World nation was the Islamic Republic of Iran: neither East nor West, in the sense of neither of the capitalist bloc nor of the socialist bloc1; and neither Eastern nor Western in its cultural mythology.2
Paradoxical as it may sound, for the first time in history, there may now exist conditions for the birth of the objective correlative for the idea of a "Third World," i.e. independence from hegemony of great powers.
1 Houman A. Sadri, "Trends in the Foreign Policy of Revolutionary Iran," Journal of Third World Studies 15.1 (Spring 1998); and Houman A. Sadri, "An Islamic Perspective on Non-Alignment: Iranian Foreign Policy in Theory and Practice," Journal of Third World Studies 16.2 (Fall 1999).
2 See, for instance, Hamid Dabashi, Iran: A People Interrupted (New York: New Press, 2006) for description of the coexistence of Shi'ism and cosmopolitanism in Iran, rooted in part in reality, in part in Dabashi's dream.