The authors conducted a UK-based future study employing the Delphi method to explore the impact of emerging computing technologies on Critical National Infrastructure (CNI). The study engaged 22 domain experts specializing in software, cybersecurity, and CNI, whose roles all include forecasting technological trends and challenges. The findings propose making Internet Services a CNI sector, and suggested the weightiest concern to be human-centric challenges around the recovery from software disasters and cyberattacks. Other major concerns also related to human factors, such as attacks via operators, and errors stemming from poorly designed human-computer interfaces. The suggested mitigation strategies therefore concentrate on human-centred approaches. Key recommendations include promoting human-focused cyber resilience, and using legislation, regulation and standards to help establish it in CNI organizations.