This year I find myself confronted with a "trilemma" -a three-horned dilemma. If, as seems highly likely, Scottish voters choose to mark the tercentenary of the Act of Union by voting the Scottish National Party into power in Edinburgh, I shall take a significant step closer to having to choose between English and Scottish citizenship. If, however, my pending application for the status of permanent resident in the United States is successful, I shall take an equally significant step closer towards American citizenship.
This is more than merely a personal identity crisis (though it is certainly that). All over the world, people are facing similar choices. Millions are strongly attracted to the idea of having their "own" little country. But other millions are just as attracted to the idea of emigrating to someone else's big country. Can they all be right? I think not.
Let us begin where I began - in Scotland. Three hundred years ago this month, the land of my birth gave up its own parliament, and hence its legislative sovereignty, under the terms of the Act of Union with England. This was far from an inevitable English takeover, since the Scots had (and retain) their own distinct legal system and Presbyterian Church.
The poet Robert Burns famously explained the reason for the 1707 Union when he wrote: "We were bought and sold for English Gold / Sic [Such] a Parcel of Rogues in a Nation", an allusion to the inducements paid to Scottish members of parliament to ensure the passage of the legislation. Money was always the basis for what was essentially a merger. All but bankrupted by their failed colony at Darien (now Panama), the Scottish elites opted for junior partnership with their English counterparts in what would be a British Empire. This arrangement worked well so long as there was an empire, financed by the English, for surplus Scots to settle, administer and defend.
Since the 1970s, however, the English gold has increasingly gone north of the border to pay surplus Scots to sniff glue and guzzle deep-fried Mars Bars. Having once been the best educated and most entrepreneurial part of the United Kingdom, Scotland has become a byword for big government, high unemployment and low achievement. Southern Ireland - once regarded by Scots like me as a benighted outpost of Popery and poverty - has eclipsed Scotland at everything from foreign direct investment to football.
The answer, argue the Scot Nats, is independence. And the "Celtic Tiger" is not their only role model. The SNP website also lauds the achievements of Australia, Estonia, Finland, Iceland, Montenegro, New Zealand and Norway, all places where "independence has worked".
It is, of course, a little premature to conclude that independence has worked in Montenegro, which has enjoyed self-government for less than eight months. Still, the point is superficially a reasonable one. There are indeed plenty of countries smaller than Scotland (population 5.1 million) that have prospered under their own flag. And it is not wholly implausible to imagine an independent Scotland as Finland West or New Zealand North.
On the other hand, there are plenty of countries with populations of around five million that have made rather less of a success of independence. Sierra Leone springs to mind. As does Eritrea. As does Turkmenistan. Small isn't always beautiful. The question therefore arises: Just when does it make sense for a people to go it alone?
The past century has seen a remarkable global experiment in what used to be called "self-determination", so we have plenty of evidence to go on. Back in 1913, around 82 per cent of the world's population lived in some 14 empires. Nation states were the exception, not the rule. But two world wars, a depression and a spate of revolutions shattered the old imperial order, ushering in an era of almost incessant political fragmentation. In 1946, there were 74 sovereign states in the world. By 1995 there were 192.
Today, Scotland is very far from the only country bidding to follow Timor-Leste and Montenegro, the newest members of the United Nations. The majority of the population of the Serbian province of Kosovo, which is less than half the size of Scotland, are eager to secede from Belgrade. If civil war leads to partition in Iraq, that country's 26 million people may have to choose between Kurdish, Sunni and Shiite statelets.
From a strictly economic point of view, the size of a country does not seem to matter much. Some small countries do very well (think Singapore and Switzerland, not to mention tiny Liechtenstein and Monaco), but some do very badly (Guinea-Bissau). Some big countries are very rich (the United States), but some are very poor (Bangladesh). Statistically, there's no relationship worth talking about between total population and per capita income.
So why doesn't Oxfordshire secede from England? Why doesn't our local village declare independence? Come to think of it, why don't I just establish Fergusonia as an enlightened, absolutist monarchy with free beer and an income tax rate of 1 per cent?
The arguments against independence come down to two interrelated things: power and culture. Though the small and smart can beat the big and blundering on occasion, in general there really are economies of scale when it comes to warfare. There are also economies of scale when it comes to communication. Most of humanity's greatest achievements, from Ming China to the Victorian Empire to 20th century America, have come where large numbers of people have been able to exchange ideas in a common language.
If the Scots all spoke Gaelic, the argument for independence would be more compelling. The reality is that they mostly watch English television programmes and read English newspapers. On the other hand, if the British Isles were menaced by a ferocious foreign invader, the argument for Scottish independence would collapse. There is safety in numbers after all.
This sheds light on the peculiar character of our age. Thanks to air transportation and electronic communications, the spread of language has become disconnected from the realm of politics: English now serves as a global lingua franca without needing the old agencies of conquest and colonisation. At the same time, the decline of expansionist empires has reduced the hazards of being a small country.
The question is whether or not that might change in the future. There are 21 countries in the world with populations greater than 60 million, of which the largest by far are China and India, each more than a billion strong. These are the giants, the heirs of past empires or recent high fertility. Of the remaining 171 countries, only 16 have more than 30 million people and only 22 more than 15 million. The rest are mere national dwarfs, states that would struggle to survive in a world where war was more commonplace and communication more expensive.
Imagine, then, a dangerous world, in which most of the world's population chose, or were compelled, to inhabit empires. China's, India's, Russia's are easy to imagine because they already exist. Would a new Persian empire arise in the Middle East? Or a restored Sunni Caliphate? Would the dream of Simon Bolivar belatedly be realised in Latin America? And what would we choose? Would the Scots and the English alike become citizens of a United States of Europe? Or, as Churchill always insisted, would we stick in time of crisis to the tried and tested union of the English-speaking Peoples?
I cannot quite believe in the Anglosphere with the same fervour that my old friend Andrew Roberts evinces in his new History of the English-Speaking Peoples. But I will say this much for the idea of Anglophone unity. It would certainly make my life easier. Until it comes, my "trilemma" will endure: do I stick with the dear old Disunited Kingdom, go west to the Big Country that is America, or head home to the People's Republic of Caledonia?
History is telling me that size isn't everything. But it's not nothing either.