The aim of the contribution is to discuss the methodological issues that emerged from recent studies on diplomatic negotiation, focusing on some useful elements for a comparison between the acquisitions of the social sciences and the historiographical approach. In search of continuity and breaks in the European diplomatic tradition, social sciences show a widespread trend to link current analysis on this topic with the first forms of a ‘negotiation theory’ drawn up between the Seventeenth and Eighteenth centuries by authors such as Richelieu, Callières, Pecquet. A strong intertwining of tools of sociology and psychology on the one hand, and a historical approach on the other, emerged in particular from the investigations into the context of the <i>face-to-face</i>: to understand what happens in the diplomatic entretien it is necessary - today as in the past -, to decipher aspects such as the communication style, the formulas of courtesy, the forms of behavior of the negotiators and the actors involved.
