The missiles could be emplaced in and launched from any surveyed site in minutes, and because the guidance system was self-correcting, the missile system possessed a genuine "first strike capability". Furthermore, it was estimated that the missiles (deployed in West Germany) could reach targets in the western Soviet Union within four to six minutes of their launch. These capabilities led Soviet leaders to believe that the only way to survive a Pershing II strike was to preempt it. This fear of an undetected Pershing II attack, according to CIA historian Benjamin B. Fischer, was explicitly linked to the mandate of Operation RYaN: to detect a decision by the United States to launch a nuclear attack and to preempt it.