Since the 1980’s, a worldwide urbanization process has lead to the drastic rise in both the number of metropolises and their spatial imprint. Along with their generalization, inequalities and low intensity violence have both intensified. In some contexts such as Brazil or Mexico, their extent questions the traditional divide between a conventional and external use of military forces and their intervention in so called “internal wars”. Far from being a passive context of engagement, metropolises have become both epicenters of social violence, warfare targets and leveling environments for the military. Drawing from its experience in urban battles in recent years and flowing several regular armies, the French military has incorporated urban combat into its doctrines in an attempt to avoid the tactical trap metropolises represent. This research paper delineates these evolutions as well as their implications for military functions in several countries.