DESTROYING THE WORLD TO SAVE IT: Aum Shinrikyo, Apocalyptic Violence, and the New Global Terrorism, by Robert Jay Lifton. Holt/Metropolitan, 374 pp., $26.

A prominent scholar in the psychology of genocide has good and bad news for those who feel paranoid about random, mass killings by fanatics:

We may not be so paranoid after all.

In his book on the Aum cult, responsible for the deadly 1995 sarin gas attack on the Tokyo subway, Robert Jay Lifton sounds a chilling alarm about an invisible new demon stalking the human race. Lifton says Aum has ushered us across a historic threshold into an age when religious zealots seeking to kill all their enemies -- if not destroy the world -- finally have the biological and chemical means to realize their age-old fantasies.