When independence was declared in Soviet-occupied Vienna and people danced Johann Strauss’s “Blue Danube” waltz on the Ringstrasse to the music of a Soviet military band, World War II was still underway. On the day following independence—April 28—August Eigruber, the Nazi regional leader for Upper Austria, ordered the gassing of resistance fighters in the Mauthausen concentration camp. In the first week of May, after Adolf Hitler’s suicide in Berlin, men of the Waffen-SS killed 228 Hungarian Jews in the leafy little town of Hofamt Priel in Lower Austria.

This year, Europe celebrated the 80th anniversary of the end of World War II and the beginning of what came next. The declaration of Austrian independence on April 27, 1945, marked an early step out of one era in the history of the country and the continent into another. Viewed from a distance, such moments can look like smooth, frictionless transitions, mere points on a timeline. We easily forget how open the future still was, how turbulent and uncertain the contemporary setting.

This year, Europe celebrated the 80th anniversary of the end of World War II and the beginning of what came next. The declaration of Austrian independence on April 27, 1945, marked an early step out of one era in the history of the country and the continent into another. Viewed from a distance, such moments can look like smooth, frictionless transitions, mere points on a timeline. We easily forget how open the future still was, how turbulent and uncertain the contemporary setting.

When independence was declared in Soviet-occupied Vienna and people danced Johann Strauss’s “Blue Danube” waltz on the Ringstrasse to the music of a Soviet military band, World War II was still underway. On the day following independence—April 28—August Eigruber, the Nazi regional leader for Upper Austria, ordered the gassing of resistance fighters in the Mauthausen concentration camp. In the first week of May, after Adolf Hitler’s suicide in Berlin, men of the Waffen-SS killed 228 Hungarian Jews in the leafy little town of Hofamt Priel in Lower Austria.

For the newly proclaimed republic, the political future was anything but certain. The new provisional government was at first recognized only by the Soviet Union. Not until Oct. 20, 1945, was the new state recognized by Britain, France, and the United States through a resolution of the Allied Control Council. And one of the fascinating features of the refoundation of the republic was its recursive quality: Article 1 of the 1945 declaration of independence stated unequivocally that this was not an act of foundation but one of “reestablishment,” to be carried out in the “spirit” of the 1920 constitution, drawn up by a defeated Austria in the aftermath of World War I.

In order to plot a path into the future, people looked to the past. And when we look back today on the 80 years that have passed since that act of reestablishment, they seem at first glance to fall into two very different halves. The first, which lasted from the end of World War II until 1989-90, was marked, in Europe at least, by a lasting peace, comparable with the decades of geopolitical stability that followed the 1814-15 Congress of Vienna. A more drastic contrast with the chronic instability and polarization of 1914-45 could scarcely be imagined. The West entered an era of public tranquility and economic growth, supported by the United States. The time of street fighting, coups, and authoritarian experiments was over.

There was plenty of violence and conflict in the world at that time, but the turbulence was contained within a bafflingly simple structure: the bipolar stability of the Cold War, underwritten by the standoff between two nuclear super