For more than 50 years, UNESCO has been questioning the delimitations and the reality of cultural borders. The East-West Major Project (1957-1966) illustrates UNESCO's initial universalist conception and its will to encourage cultural unity. It reveals a progressive turn around in UNESCO's cultural politics, which led UNESCO to develop a more synthetic conception, allying promotion of both cultural unity and cultural diversity. Since the 1960s, UNESCO has tried hard to safeguard the world cultural heritage, notably in Africa, where it appeared to be endangered. The creation of the World Heritage List in 1972 and the attempt to set up a "New World Information and Communication Order" in 1980 were important steps. Several Conventions were adopted. The Convention on Cultural Diversity (2005) is particularly important, because it together emphasizes the diversity of the different cultures and affirms the Universalist idea of all cultures belonging to a common cultural ground. It therefore refutes Samuel Huntington's conception of an inevitable clash of civilizations: the UNESCO's convention goes against the idea that cultural borders would be factors of conflict. It constitutes an attempt of synthesis between universalism and multiculturalism. Yet the UNESCO's actions remain too scattered, and the efficiency of the UNESCO's conventions is very poor. Besides, the UNESCO's instruments have also pernicious effects: they are often used as instruments for political or economical targets. Now, UNESCO should not only promote the idea of "cultural diversity" and celebrate "cultural borders" and "intercultural dialog", but above all clearly distance itself from the idea of liberalizing culture and from WTO politics. Indeed, liberalizing culture increases social inequality and therefore deepens the "cultural gap" between people. UNESCO should take more concrete steps to allow every people to partake in cultural life. [ABSTRACT FROM AUTHOR]