In China, 30 years ago, an audacious public protest in the capital's central square pushed China's autocrats to the brink. Two years later, when the Soviet Union imploded, the ruling Communist party's most relentless internal critic became Russia's president and dominant political figure.
Ascendant America had no serious rival. In Europe, West welcomed East. Among the world's most advanced countries, there seemed little left to fight over. The end to a century of conflict appeared to ensure democracy had carried the day.