Collective defense is a coordinated response to a common security problem by two or more countries. The core of collective defense is political: a commitment by different nations to come to each other’s aid if attacked. Existing collective security arrangements for the U.S. and its allies were designed for one kind of threat. Now they must deal with others, including new threats, if they are to remain relevant to national security. In particular, the U.S. and its allies agree that it would be useful to extend collective defense arrangements against potential cyberattacks, but implementation has proven difficult because of the operational aspects of cyberattack, the ways in which cyberwar will be waged, its limitations and effects, and what must be defended.
The targets of a cyberattack are an opponent’s computers. The attack must penetrate network defenses to insert a malicious program on the target device. These targeted devices do not always resemble personal computers, but could include special-purpose computers whose source of instruction and control is transmitted over a network. Special-purpose computers, which include industrial control systems used in critical infrastructures, are embedded in an expanding range of machinery and infrastructures, including advanced weapons that increasingly rely on software; the ability to disrupt their operations can produce an effect similar to that of a kinetic weapon. Physical disruption or destruction through a cyberattack has been rare, but several countries, including most leading military powers as well as nations like Iran, have acquired such capabilities.
An attacker can also erase, corrupt or steal data and disable online services. A September 2012 attack by Iran against the Saudi Arabian oil giant Aramco permanently erased data from 30,000 of the company’s computers. In a conflict, data could also be jumbled, causing supplies to be misrouted; ships, aircraft or men to be misdirected; or intelligence to be manipulated. The effect of such a manipulation would be to shatter a commander’s confidence and to increase hesitancy and uncertainty, which would provide the opponent with an advantage. A more subtle approach would see an opponent exploit network access to gain intelligence advantage. Cyber-espionage offers benefits similar to those provided to the Allies by the World War II Ultra signals intelligence program, which allowed the Allies to decrypt the Germans’ most sensitive communications and make them available to Allied commanders.