“But states have difficulty evaluating cybersecurity threats. If a state does detect an intrusion in one of its vital networks and if that intrusion looks to be from another state, what should the state suffering the intrusion conclude? On the one hand, it might be a defensive-minded intrusion, only checking out the intruded-upon state’s capabilities and providing reassuring intelligence to the intruding state. This might seem unsettling but not necessarily threatening, presuming the state suffering the intrusion was not developing capabilities for attack or seeking conflict. On the other hand, the intrusion might be more nefarious. It could be a sign of some coming harm, such as a cyber attack or an expanding espionage operation. The state suffering the intrusion will have to decide which of these two possibilities is correct, interpreting limited and almost certainly insufficient amounts of data to divine the intentions of another state. Thus Chapter Four’s argument is vitally important: intrusions into a state’s strategically important networks pose serious risks and are therefore inherently threatening. Intrusions launched by one state into the networks of another can cause a great deal of harm at inopportune times, even if the intrusion at the moment of discovery appears to be reasonably benign. The intrusion can also perform reconnaissance that enables a powerful and well-targeted cyber attack. Even operations launched with fully defensive intent can serve as beachheads for future attack operations, so long as a command and control mechanism is set up. Depending on its target, the intrusion can collect information that provides great insight into the communications and strategies of policy-makers. Network intrusions can also pose serious counterintelligence risks, revealing what secrets a state has learned about other states and provoking a damaging sense of paranoia. Given these very real threats, states are likely to view any serious intrusion with some degree of fear. They therefore have significant incentive to respond strongly, further animating the cybersecurity dilemma.”