sentences:  Nosenko said that, while the KGB had conducted surveillance of Oswald, it had never tried to recruit him.This issue was critical because KGB involvement with Oswald might suggest Soviet involvement in the Kennedy assassination – a prospect that could have propelled the Cold War into a nuclear war.Nosenko insisted that after interviewing Oswald it was decided that Oswald was not intelligent enough and also "too mentally unstable," a "nut" and therefore unsuitable for intelligence work.