U.S. analysts and scholars are debating the effectiveness of deterrence in the cyber space, and one major issue is the problem of attribution. Although the U.S. could send deterrent signals to potential adversaries in a way resembling nuclear deterrence, there are difficulties in doing it. Once the U.S. cyber capabilities were exposed, its adversaries would be in a better position to develop countermeasures. In light of the serious consequences of a retaliatory cyber-attack, many in the U.S. prefer deterrence by denial, but it may not necessarily succeed in dispelling the attacker’s idea of launching a cyber-attack. Moreover, other problems confronting cyber-deterrence include how to control conflict and escalation in the cyber space. Prescriptions abound in the U.S about how to implement a successful cyber-deterrence strategy.