Months ago when Mikhail Gorbachev began to move more visibly around the power circuit of the Soviet Union, U.S. intelligence analysts started to feed background on him into Ronald Reagan's morning reading. There was an assumption among the experts that something was bubbling up in the Kremlin's gerontocracy, whose members were expiring with discouraging regularity. After 67 years there were signs that the old group of Soviet leaders, steeped in the traditions of the revolution and shaped by the horrors of World War II, was giving way to a new generation.
In the President's intelligence report, a thick black notebook with...