Cyber activities, particularly those of a cross-border nature, have not yet been subjected to international regulation despite the fact that cyberspace has become a strategic domain for all States. This lack puts at risk the efficacy of national defence strategies inasmuch as the decision maker remains inactive because assailed by the so-called response crises. That is the dilemma arising from the doubt that in case of a cyber threat, or cyber attack, any operative choice may lead to a violation of international law. In this scenario States are obliged to reconsider new defence strategies and theories of deterrence such as that of deterrence by denial, which is primarily based on the concept of resilience in order to reassure service contin...