This episode's headline: Breakthrough; Facing the Music; Identity Crisis. The guests include AMB. MICKEY KANTOR, U.S. Trade Representative; LORI WALLACH, Citizens Trade Committee; REP. SANDER LEVIN, [D] Michigan; BILL RICHARDSON, [D] New Mexico; CORRESPONDENTS: KWAME HOLMAN; RICHARD OSTLING. Byline: In New York: ROBERT MacNeil; In Washington: ROGER MUDD