As the European Commission’s Vice-President Margaritis Shinas put it in July 2020 when unveiling the European Commission’s new strategy for internal and external security over the next five years, “From protecting our critical infrastructure to fighting cybercrime and countering hybrid threats, we can leave no stone unturned when it comes to our security” (Sánchez Nicolás, 2016). Said new strategy places a particular emphasis on critical infrastructure protection, which plays a crucial role in the realm of the security of the European Union (EU). But what exactly do we mean by ‘critical infrastructure’? Why do we need to develop an effective critical infrastructure protection strategy? And how can defence planners help achieve what European policymakers have not managed so far?