This chapter throws light on ethical concerns regarding cyber war or cyber terror. Computers have contributed to revitalizing the realm of conflict in three principal areas. First, in terms of conventional military operations, computers have completely revolutionized communications, making complex new modes of field operations possible. Next, computers have made it possible to analyse oceans of sensor data quite swiftly, enabling the military, intelligence and law enforcement communities to take action in ever more timely and targeted ways. This powerful new analytic capacity, it must be noted, can serve aggressors or defenders equally well, whether they are nations or terrorist networks. Last, the growing dependence of societies and their militaries on advanced information and communications technologies has given birth to cyberspace-based forms of strategic attack, designed to cause costly, crippling disruptions. In sum, whether nation or network, there may be sound ethical reasons for embracing cyber warfare and/or cyber terror.