This episode's headline: Death Threat; Bush Budget - 1989; Aftershock. The guests include SHAUL BAKHAS, Middle East Historian; DANIEL PIPES, Middle East Analyst; DR. WILLIAM ROPER, Health Care Financing Adm.; DR. JAMES TODD, AMA; MICHAEL BROMBERG, Federation of Amer. Health Systems; CORRESPONDENTS: TOM BEARDEN; THEODORE BOGOSIAN. Byline: In New York: ROBERT MacNeil; In Washington: JAMES LEHRER