The waves of terrorist attacks against European cities since the mid-2010s have sent shockwaves in European local and regional authorities, which found themselves confronted with the complex challenge of securing their urban public spaces without turning them into “bunkers”. What can cities do to render their public spaces more safe, inclusive and open to all? How to collaborate more efficiently with national authorities, but also police forces and all the other relevant local stakeholders? How to take into account new technological developments? How to better involve citizens and civil society?