Propaganda and cultural diplomacy are sometimes used to mean the same thing. Through French efforts to influence the United States during the first part of the XXth century, we’ll attempt to determine if propaganda and cultural diplomacy are a unique object whose designation may vary depending on the audience, aims and circumstances or if they are, on the contrary, two distinct actions separated by nature, that would both benefit French interests, but using two distinct means of achievement. In analysing the influence and achievements of French diplomacy in the United States, its cultural character favorable to reach all kinds of political, commercial or touristic aims, we would like to point out first the importance of the “receiver” (meaning in this case the american society), a sine qua non condition for success in any effort of foreign influence; second the deep complexity of various networks, both American and French, public and private and the enormous diversity of cultural actors. Moreover, these agents play a double function of agents belonging to the diplomatic web, and cultural links as vectors of American-French cultural relations.