In 1990 management consultant Kenichi Ohmae published a book called The Borderless World, whose title captured the spirit of globalisation. Over the next almost 25 years, developments in business, finance, technology and politics seemed to confirm the inexorable decline of borders and the nation states they protected.
No international affairs conference was complete without somebody remarking that the world's most important problems could no longer be tackled by nations acting alone. The emergence of the Internet bolstered the idea that borders no longer matter. In a borderless world of bits and bytes, the traditional concerns of nations - territory, identity and sovereignty - looked as anachronistic as swords and shields.
But last week, 45 per cent of Scots voted in favour of setting up a nation independent from the United Kingdom. The referendum was watched eagerly by separatist movements in Catalonia, Tibet, Quebec and elsewhere. Separatist movements are one facet of the resurgence of nationalism. In Europe, Asia and the Middle East, nationalist politicians are on the march - even in well-established states.
The most dangerous nationalist in Europe is Russia's President Vladimir Putin, who has annexed Crimea, proclaiming his right, indeed duty, to protect Russian speakers wherever they live. As many have nervously noted, this potentially gives Russia an excuse to intervene right across the territory of the former Soviet Union.
Even as the European Union struggles to muster opposition to Mr Putin, there are nationalist politicians within Europe who are openly sympathetic to him, such as Ms Marine Le Pen, leader of France's National Front.
In Germany, the rising political force is the Alternative for Germany, which argues that German interests have been subordinated to those of Europe.
Even in prosperous Sweden, the Sweden Democrats, a far- right party, has just won 13 per cent of the votes in a general election. In Hungary the Fidesz government has clear authoritarian tendencies and a keen interest in the fate of Hungarians beyond its borders.
The three most powerful Asian countries - China, Japan and India - are led by charismatic nationalist leaders. China's President Xi Jinping, Japan's Prime Minister Shinzo Abe and India's Prime Minister Narendra Modi use a similar rhetoric of national revival as a spur to economic and social reform at home. Internationally, however, their nationalism clashes in the form of border disputes between China and its two big neighbours, raising the risk of war. If we are living in a borderless world, somebody seems to have forgotten to tell the Chinese, Japanese and Indians who sometimes seem obsessed by the demarcation of their territory.
At first sight, the Middle East appears to be an exception to this pattern of resurgent nationalism. The most dangerous new movement in the region is the Islamic State in Iraq and Syria, an extremist movement that disdains national boundaries. But Egypt, the most populous Arab state, has taken a nationalistic turn, as its military- led government seeks an alternative ideology to Islamism.
What accounts for this strange global resurgence of nationalism when so many economic and technological forces push in the opposite direction?
One answer is that the prophets of globalisation probably underestimated the residual power of nationalism. If you spend your time in airport lounges and at global conferences, it becomes easy to forget that most people lead lives more rooted in a particular place. Indeed, the disorientating effects of globalisation probably encourage people to look for reassurance and meaning in things that are more local or national, whether it is a common language or a shared history. Suspicion of globalisation and international finance also received a huge boost after the economic crisis of 2008.
Poverty and war are leading to mass movements of refugees, particularly into Europe and the safer parts of the Middle East. There is nothing like mass migration, or a refugee crisis, to make people conscious of the enduring importance of borders. A backlash against immigration has been central to the rise of nationalist parties such as the French National Front, the Sweden Democrats and Britain's UK Independence Party.
Perhaps most dangerously, the sense that the global order is newly unstable may be stoking nationalist sentiment, as countries or separatist movements see an opportunity to push their previously dormant agendas. Mr Putin had made regretful noises about the collapse of the Soviet Union many times in the past. Now he feels strong enough to do something about it.
Unfortunately, since nationalist movements define themselves against foreigners, they often provoke rival nationalist movements next door. You could see this even in Britain, where the rise of Scottish nationalism created some hostility to the Scots among the English.
The same dynamic is in play, in a much more dangerous form, in Asia. In China, a recent poll suggested that more than 50 per cent of the population expects war with Japan. Another opinion survey suggested that over 90 per cent of Japanese had a negative view of China.
In a more optimistic age, it was a Japanese thinker - Mr Ohmae - who popularised the notion of a borderless world. For 25 years, his insight had seemed powerful and prescient. Sadly, it now looks increasingly out of tune with a world in which nationalism is resurgent.
THE FINANCIAL TIMES