Let us assume that states agree to a set of rules for the use of cyber weapons — for example, not attacking critical infrastructure during peacetime. What happens when a state violates one of those rules — is it possible to define who is responsible in this case? Enforcement techniques in use or under consideration include diplomatic pleas and threats, economic sanctions, indictments, public shaming, joint investigations, recalling diplomats, as well as military and information countermeasures. Such techniques are proving ineffective and potentially destabilizing. Mr. McConnell will outline a proposed enforcement regime to improve security and stability in cyberspace.