In 2007, Ivan R. Dee published Pacepa's book "Programmed to Kill: Lee Harvey Oswald, the Soviet KGB, and the Kennedy Assassination" that argues Lee Harvey Oswald was recruited as a KGB agent. According to Pacepa, Soviet Premier Nikita Khrushchev ordered the assassination of Kennedy, then changed his mind but was unable to stop Oswald. Pacepa wrote that Jack Ruby was subsequently instructed to kill Oswald in order to silence him. The work was said to rely heavily on the work of the Warren Commission, the House Select Committee on Assassinations, and Edward Jay Epstein.