Somebody born in Lviv in 1914, who died in 1992 and never moved out of the city, would have lived in five different countries during the course of a lifetime. In 1914, Lviv, then called Lemberg, was part of the Austro-Hungarian empire; by 1919 it was part of Poland and became Lwow; in 1941 it was occupied by the Germans; after 1945, the city was incorporated into the Soviet Union; and then in 1991 it became part of newly independent Ukraine.

Most of these changes were accompanied by warfare and bloodshed. So when it was suggested last week that, a few years ago, Russian president Vladimir Putin had proposed to Donald Tusk, then Polish prime minister, that Ukraine should be partitioned once again – with Russia claiming the eastern territories, and Poland Lviv and other parts of western Ukraine – there was an uproar.

The details of the Putin-Tusk conversation – and indeed whether it ever really took place – were swiftly made murky by denials and clarifications on all sides. But the furore over the idea of a partition of Ukraine was still telling. For it revealed the deep and justified fear in Europe that national boundaries might shift once again, across the continent, with all the dangers that implies.