The writing is the process by which the twin cities, separated by a boundary that, although virtual, remains at the level of state sovereignty, they become a single "new city". Different forms of possible inter-penetrations between the two cities are considered, and then it is possible to draw that current Gorizia and Nova Gorica are transformed into a new city, to be called Gorizia/Gorica or Isonzopoli/Sočepolis. To check what is used in the construction of forecast scenarios (now, after 5 years, 10 years, 15 years) on three hypotheses of relationships between the current two cities: that they remain separate as now, they develop more or less strong "differentiated integration", they build a new city and "normal", i.e. the same as all the other cities except for two constraints may come from the fact that even if there is a boundary between two sovereign powers, even if disabled. Six possible final scenarios (to 2025) are eventually considered: between the "new city" impossible, unrealistic scenario, the negative scenario ever, the incomplete "new city", the scenario of "blocking realistic", and finally the "new town" optimal. The possibilities of realization of individual scenarios are evaluated as well as their extensibility to other sister cities, including the Jerusalems that are co-living in Jerusalem.
Keywords: "Città nuova", città gemelle, scenari, previsione, Gorizia/Gorica