Beyond controlling mobility of undesirables, the function of the building up of “fences” on territorial boundaries is also to reassure fenced-in citizens. By analyzing the cases of Israel and the USA, my research investigates how the fenced territory becomes the place of a public performance aimed to reassure Israeli and US citizens. The starting point of the demonstration is that such defense policies nourish social mobilizations (in Israel from 2001 in favor of a “security fence” in the West Bank; in Arizona from 2010 in favor of a “border fence” with Mexico). I rely on analyses of representations, actions and security practices of such mobilizations to investigate national and geopolitical specificities. Beyond these specificities, I compare three analogous political operations by pro-fence movements in their political systems. First, they construct situations of mobility and presence of undesirables as problematic. Second, they securitize these situations as a security issues calling for a military response. Finally, they diffuse pro-fence framing by collective and dissenting actions against governments. Thus, they contribute to maintain a consensus over the role of the military in the construction and the management of a “public problem” of mobility in these two societies. In conclusion, I will insist on research avenues to dissect border fence policies around these three operations, especially in order to dialogue with the bordering of the Mediterranean.