This chapter examines resistance by urban-based opposition groups to the implementation of national political agendas. It investigates two cities where national policies operate amid contested citizenship, based on seven months of in-country research and 122 interviews conducted in 2015 and 2016. The political goals of Israeli sole sovereignty in Jerusalem and Northern Ireland’s shared future in Belfast are obstructed during local implementation. Difficulty in implementing national policy directives in urban space provides opportunities that mobilized ethnic groups exploit to counteract national dictates. This capacity of urban opposition occurs in distinctly different national programmes, illuminating the inherent disruptive quality of intransigent urban interests.