'''Silent Horizon''' is a United States [[military simulation|war exercise]] that simulates [[cyberwarfare]]. It is run by the [[Central Intelligence Agency]], an independent civilian [[intelligence agency]] of the [[Federal government of the United States|United States government]]. The war exercise was first held in 2005, and the scenario was five years in the future in which an attack on the same scale as the [[September 11 attacks]] takes place and includes hackers hired by anti-American organizations. The Information Operations Center at the CIA ran the war exercise, and around 75 officials, mostly from the CIA, participated in the exercise, reacting to different attacks. The exercise took place in [[Charlottesville, Virginia]].<ref>{{cite news | last=Bridis | first=Ted | url=https://www.usatoday.com/tech/news/techpolicy/2005-05-26-cia-wargames_x.htm | title='Silent Horizon' war games wrap up for the CIA | work=[[USA Today]] | publisher=[[Associated Press]] | date=May 26, 2005 }}</ref> The CIA did not make public its findings.<ref>{{cite book | last=Axelrod | first=Evan M. | year=2009 | title=Violence Goes to the Internet: Avoiding the Snare of the Net | publisher=Charles C Thomas | isbn=978-0-398-07882-9 | page=178 }}</ref> Edward V. Linden, in ''Focus on Terrorism'', said, "The national security simulation was considered significant because many U.S. counterterrorism experts feel that far-reaching effects from a cyberattack are highly unlikely."<ref>{{cite book | last=Linden | first=Edward V. | year=2007 | title=Focus on Terrorism (Volume 9) | publisher=Nova Science Publishers | isbn=978-1-60021-709-8 | pages=47–48 }}</ref>
[[Richard A. Clarke]] said in 2010 that Silent Horizon has been taking place every year since 2007.<ref>{{cite book | last1=Clarke | first1=Richard A. | last2=Knake | first2=Robert | year=2010 | title=Cyber War: The Next Threat to National Security and What to Do About It | url=https://archive.org/details/cyberwarnextthre0000clar | url-access=registration | publisher=Ecco | isbn=978-0-06-196223-3 | page=[https://archive.org/details/cyberwarnextthre0000clar/page/179 179] }}</ref>
==References== {{reflist}}
[[Category:Military exercises involving the United States]]