How can states respond to massive cyber-attacks targeting their society? Even though cyber-attacks have become a rather omnipresent phenomenon in international relations, there is still no clear answer to this question. Many ways of responding have been explored, but none of them have proved unconditionally effective in retaliating against a large-scale cyber-attack so that further attacks will be deterred.
This policy brief by Sico van der Meer concisely explores the policy instruments available to states experiencing a massive cyber-attack, as well as the potential effects and risks of these tools. A distinction will be made between diplomatic and non-diplomatic responses, and the effectiveness of both types of tools will be weighed as well. Examples of the actual use of the instruments will be particularly found in US policies, because this state has been most active in (publicly) experimenting with the various tools in searching for effective means of retaliation against and the deterrence of large-scale cyber-attacks.