 In that role, he was involved in Operation Anadyr and the Cuban Missile Crisis.During the latter, he stayed in the Kremlin and assisted the Soviet leader, Nikita Khrushchev.In 1963, when Colonel Oleg Penkovsky was arrested, Ivanov committed negligence in his work; Khrushchev wrote in his memoirs that he did not recall the exact deed, but that it might have ended in a security risk.