Taking part in the solutions of main problems at the dawn of the third millennial, peace, development and environnemental protection in the world appears like an imperative of the international community. In so far as instrument of intellectual cooperation, Unesco plays an essential role.The recent debates about its role and missions involved the 1984-85 crisis that led to the withdrawal of three members states and particularly two founder members: the United States of America and the United Kingdom.This article deals with the withdrawal processus of the United States of America, the main contributor of the Organization and analyses the efforts made by both directors general the former one Mr. Amadou Mathar M'Bow as well as the present one Mr. Federico Mayor to preserve Unesco universality.