Artificial intelligence is turning organisations into post-digital enterprises, where intelligent systems decide and act inside core processes - and open a class of risk that frameworks built for conventional infrastructure do not address. This study develops and empirically examines the model: a structured survey of 212 technology, security and business leaders analysed with CFA and SEM, alongside interviews with senior security experts. All five hypotheses are supported. Cognitive security capability is the strongest driver of enterprise resilience, and governance strengthens it.