Last summer, when I was checking the proofs for my book about the Habsburg Empire, Danubia, I found myself reflecting on the way that across Central Europe over the past century and a half different forms of nationalism have done almost untold damage. Wherever I travelled there were entire towns whose populations had been killed or expelled at the command of one form of nationalist zealot or another. My conclusion (which I am sure is an uncontentious one) was that anyone who makes exclusive claims based around flags, songs or mystical and immemorial borders was at some base level evil — that to believe in such things, which have more in common with magic than rationality, puts the believer and his disciples en route to catastrophe. And then I thought about Alex Salmond.

The Habsburg Empire, which was destroyed during the course of the First World War, joined together part or whole of 12 modern European countries and stretched from the Alps to western Ukraine. It was hardly a model of rationality and could often be cynical or incompetent – but it seems like a vision of paradise compared to the nihilistic disaster that unfolded for its inhabitants from 1914 to the end of the Cold War. Several generations found themselves savaged by all the most horrible elements in Europe's formidable armoury of creepy prejudices sprinkled with a dusting of intellectualism – what language you spoke, your religion, your political views had you herded into different camps at different times. In the end nobody won. Whatever terrible crimes the Communists carried out they at least had a salutary attitude towards the nationalists scattered across Central Europe who had done so much to support the Nazis and to poison community after community that had until then generally lived cheek-by-jowl for centuries, if not in harmony then in grudging indifference.

The lesson of the Habsburg Empire's demise is probably that multinational states are extremely valuable. They define themselves by some measure of tolerance and the heir to the throne, Franz Ferdinand, had until his assassination, planned for his accession all manner of schemes to federalise the Empire. Before the catastrophe of the First World War very few of the Empire's inhabitants imagined that independence was even a rational option. Even Tomáš Masaryk, later to found Czechoslovakia, could only imagine a federal solution – the lands of Bohemia and Moravia which he wished to have autonomy were simply filled with too many people who could never be reconciled to rule by Czech-speakers, as turned out to be the case.

This is when I started to think about Salmond. The United Kingdom is Europe's last big multinational state – and in that sense vulnerable to what nationalists love to think of as "the tide of history". But the disasters of the 20th century have perhaps taught us that there are many problems with nationalist ideas on sovereignty. Indeed the European Union was created specifically in order to neuter these problems. One hardly discussed reason why the EU might be antagonistic towards Scottish independence is that Salmond's rhetoric and reality swim in exactly the opposite direction to all the most positive European trends since 1945. While most of Europe pools its sovereignty, here is someone yet again making mystical claims for the greater virtue that would emerge from drawing a ring around a particular chunk of land.