This reaction is often focused on single events and circumstances rather than complex indicators. For that reason, this chapter analyses the evolution of public attitudes towards nuclear energy, and especially how security of supply issues affect how people view the role nuclear energy. In recent years, several opinion polls, in particular in Europe, have gauged the level of concern about these issues. The results are of interest because they shed light on one way of strengthening the political feasibility of increasing the share of nuclear energy in OECD countries, using the driver of improving the security of energy supply.