The study investigates different ways in which urbanization and its tempo influence terrorist activity. In line with other researchers investigating nonlinear effects on instability, we suggest that the influence of both of them is nonlinear, with quadratic regression being more appropriate for urbanization level impact and interaction between urbanization and its tempo being more appropriate to measure the tempo's influence. Nonlinearity has been confirmed in the robustness section of the paper, in which an alternative dependent variable distribution and a greater set of control variables were used. The findings are in line with those of other researchers who found that societies, in the process of modernization, demonstrate heavier instability than societies before modernization or those after the modernization period.