Czechoslovakia: Historian gives account of 1968 invasion "Overall, 137 people died in Czechoslovakia between August 21 and December 31, 1968," says Libor Svoboda, a historian at the Prague-based Institute for the Study of Totalitarian Regimes. In the summer of 1968, three dozen Soviet divisions, backed by Bulgarian, East German, Hungarian and Polish troops, crushed the "Prague Spring" movement that had shed censorship and introduced unprecedented press freedom. SOUNDBITESSUPPLEMENT TO VID1221551_EN