The Israeli colony of Ariel was founded in 1978. In 1998 – only 20 years later – it acquired city status (only three other colonies located in the West Bank have such status: Modiin Illit, Maale Adumim and Betar Illit). Today, it has about 20,000 inhabitants. It is both one of the most developed Israeli settlements and one of the most deeply established in the Palestinian occupied territories. We propose to discuss it, here, following a longitudinal approach to contribute to a better understanding of the territorialization of the Israeli-Palestinian conflict.We will discuss Ariel through what we call “different determinants of action”: from a spatial point of view (a geography of action in the Palestinian territories occupied by a segment of the Israeli population – but which one? – and by the Israeli authorities), from a cartographic point of view (the representation of the territory and the representation of the possibilities and/or obstacles to the geospatial resolution of the conflict; A. Dieckhoff showed, as early as 1987, the role of “separation of Samaria” that this entity was called upon to play), from the point of view of the commitment of researchers in a field whose sensitivity is only growing from the 1990s, as evidenced by the corpus of data produced by Palestinian and Israeli NGOs denouncing the construction of a colony embodying the socio-spatial dynamics of the conflict.The essential questions of housing and population (origins and diversity), but also of territorial planning are at the heart of the bundle of structuring actions which add to the complexity of the analysis. Ariel is, in fact, part of a road and public transport network which connects it to a whole set of “outposts” of colonization, but also to the economic and cultural capital that is Tel-Aviv. It became, for many,a suburb of Tel-Aviv where to live and where from to commute. More so over that Ariel is also a major “spot” for higher education with a well-endowed Israeli public university (twenty-six departments, three faculties, three schools). The recent territorial extensions of Ariel, implementing planning elements defined in 1991, demonstrate the relevance of a longitudinal approach to the determinants ofaction to understand what does Ariel tell us – its existence, its establishment, its deployment over more than forty years, its changes in status, the services from which it benefits, its housing policy – about the Israeli and Palestinian territories and the Israeli-Palestinian conflict.< Réduire