This chapter focuses on the Cancun Summit held on 22-23 October 1981 in Mexico. It describes the organization of Cancun and its discussions, as well as analyse the evaluations of it by leaders in attendance and the international press. Many developing countries, such as Algeria, were hesitant to organize a summit because they feared that it would be used by the industrialized countries to make decisions in a more favourable context than the United Nations. In the hope of assuring American participation, Lopez Portillo was charged with contacting Reagan and giving him a personal invitation to Cancun. With regard to the agenda, the ministers of foreign affairs agreed to discuss four main topics: food and agricultural development, commodities, trade and industrialization, energy, and monetary and financial questions. The faith in the Keynesian economic system, in the state's regulatory role, in the capacity of political authority to promote reforms was deeply shaken.