The talk of “sectarianism” is on the rise again in the Middle East in the wake of the Arab Spring and the sectarian violence that has ensued in the region. Since the beginning of the civil war (1975-1990), Beirut has been the paradigmatic city to discuss sectarianism. However, most studies of sectarianism in the Lebanese context have been political theses or historiographies on the relationship between sectarianism and the formation of the Lebanese modern nation state, debating whether sectarianism is a traditional primordial characteristic, a construction of the colonial and the modernization projects, or a class domination project (Joseph 1975, Khalaf 1986, Khuri 1975, Makdisi 2000; Weiss 2010). But how is sectarianism constructed, lived, and reproduced in contemporary Beirut? In order to answer this question, the paper examines the urban development of two contested southern peripheries of Beirut –Sahra Choueifat and Doha Aramoun. This 16-month study (2009-2010) was conducted through interviews with urban planners, residents, municipal officials, and former militiamen as well as archival research in official records of zoning policies, transactions in land and housing markets, and legislation of property and building laws. The paper exposes how religious-political organizations -such as Hezbollah, the Druze PSP, and the Sunni Future Movement – have transformed Beirut’s southern peripheries into frontiers of sectarian conflict through these actors’ territorial battles governed by their anticipated roles in local and regional futures of violence. For example, as a result of Hezbollah-PSP territorial battles over Sahra Choueifat, the area’s 1996 30-year master plan was changed at least 8 times in 10 years, resulting in overlapping and continuously shifting industrial and residential zones which has caused hazardous living conditions and forced displacement among its low income residents. Doha Aramoun’s building law has changed with the shifts in the political landscape that govern alliances and violence between these actors. Within the spatial logics of local and regional wars that are “yet to come,” the paper hence illustrates how the articulation of sectarianism, capitalism, urbanization, geo-political interests, and violence produces and reproduces Beirut’s geographies of the sectarian order. The paper argues that Beirut’s sectarian geographies are constantly being negotiated and reconfigured re-defining in turn what “sectarianism” comes to mean at each historical moment. The paper raises the question of whether we can locate hope for an alternative urban politics in contested Middle Eastern cities in these ephemeral, continuously changing spatial constructions of sectarian differences.