Through hostile attacks, it is possible to affect the availability of the PSN. The primary impact of hostile attacks such as coordinated nuclear attacks, limited/uncoordinated nuclear attacks, nuclear accidents, terrorism, electronic warfare, sabotage, and civil disorder on the PSN is disruption and denial of service. Such disasters impact the timeliness and quality of the delivered services. The report ``Summary of the Threat to National Security and Emergency Preparedness Telecommunications'' relies on classified source material and focuses on the hostile threat to NS/EP telecommunications [18].
It is possible for sabotage to be performed by disgruntled employees and members of adversary nations. Although the probability of sabotage is relatively low, the effect on NS/EP is high. The concentration of telecommunications resources increases the effects of strategic sabotage attacks because more telecommunication resources will be affected. The use of optical fiber increases the effects of strategic sabotage attacks because optical fiber technology is diminishing the number of geographic transmission routes, increasing the concentration of traffic within those routes, reducing the use of other transmission technologies and restricting spatial diversity.