Numerous intelligence updates to President Johnson regarding unrest and the potential invasion of Czechoslovakia during the Prague Spring. Updates are provided in the form of cables from the American Embassy in Prague, the White House situation room, the CIA and Walt Rostow. Documents reflecting U.S. observations of the failure of the Prague Spring and the reactions of Eastern European states including Romania, Hungary and Poland. Includes the American Embassy in Moscow’s commentary on the effects of Czech developments on the internal political situation of the Soviet Union. Also includes Nathaniel Davis's analysis of the Warsaw Summit and Communist Central Committee meetings on the Prague Spring.