This episode's headline: Korean Plane Reaction. The guests include YITZHAK TARASULO, Soviet Defector; ARKADY SHEVCHENKO, Former Soviet Official; WILLIAM HYLAND, Carnegie Endowment for International Peace. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor; DAN WERNER, Producer; JUNE CROSS, DAVID T. SHAPIRO, PATRICIA ELLIS, Reporters