There is a growing scientific and political awareness that commons are a positive management regime vis-à-vis human well-being and environmental conservation. Concretely, this paper focuses on the Sinjajevina-Durmitor massif mountain range in Montenegro, the second largest mountain pasture in Europe, an over 1,000 km2 limestone highland between 1.600 to 2.500 masl, which has numerous pastoral commons within it making a cluster of community-conserved areas as defined by the ICCA Consortium. The highland pastoral settlements (katuns) dispersed over the territory of Sinjajevina, belong to 8 tribal groups, and each katun more or less coordinates with the others but most importantly, they have their own rules of governance eachone, concerning timing of access to pastures and the ways of using them.The Delegation of the EU to Montenegro co-funded a nearly 300.000€ study concluding that a Regional Natural Park for Sinjajevina should be created and that was expected by the end of 2020. Nevertheless, last September 2019, midway through the process, the Montenegrin right-wing nationalist Government officially inaugurated an artillery camp in the heart of these inhabited pastures and began military training in collaboration with important NATO allies (USA, Italy, Austria and Slovenia). Due to macro geopolitical reasons, still obscure to the public, an over 7.000 ha military ground within the Tara basin UNESCO Biosphere Reserve and surrounded by a multiplicity of other protected areas, has started to expel local farmers. In such context, this paper will present how an initial ethnographic project of the most important pastoral commons of the Balkans has shifted into an engaged anthropology action-research project, and how this has opened many doors to the research itself at the same time as it has given full sense to it by contributing to the protection of these valuable highland living rural socio-ecosystems through its involvement in the local and global uprising against Sinajevina’s militarization.