For some time now I have been arguing that the whole of the UK must respond to the clear demand for constitutional change, and earlier this week I proposed a timetable to deliver a stronger Scottish parliament. But Scots are also leading the discussion on a new idea of citizenship for the global era, one that recognises the strength of national identity and wants to bring power closer to the people. Yet it also understands that, after wave after wave of globalisation, our ability to seize opportunities and make rights come alive is now being shaped within a vast network of global economic interrelationships – a network over which we feel we have too little power.

When I set out plans for a more modern constitution in 2007 I was thinking of a new citizenship for the global era. Our later measures – parliament's power to declare peace and war, MPs to be subject to a right to recall, an end to the royal prerogative, an elected Lords – were about a 21st-century democracy, with citizenship to be founded on a new bill of rights and responsibilities and, in time, a written constitution. There was little public or media appetite for change at that time. The MPs' expenses crisis should have triggered sweeping reforms but, in the wake of the global economic collapse, all talk of constitutional change had to take second place to preventing an economic recession from turning into a full blown depression and to getting us back to growth.

But across Europe we are now seeing the rise of both anti-establishment, anti-immigrant parties of the right and secessionist movements, such as the one in Scotland. It is not just because of the referendum that Scotland has moved centre stage – there are two other reasons. First: because of Scotland's experience of the most dramatic deindustrialisation we have become more aware of how our future rights and opportunities are tied to managing globalisation better. And second: because of our unique experience of being a stateless nation – which has for 300 years seen benefits in cooperation across nations – we have a unique contribution to make to what citizenship means for a more interdependent world.

Twice since 1707, Scots have redefined ideas of what citizenship means. First, the Scots Enlightenment gave the world the idea of civil society, of a citizen who is neither subject nor just consumer, and of a modern citizenship that stands between markets and states. Then, as they confronted the turmoil and injustices of the industrial revolution, Scots led the way to a 20th-century citizenship that guarantees social and economic as well as civil and political rights.

In the post-union, stateless Scotland of the 18th and early 19th centuries, Scots Enlightenment philosophers taught people to think of themselves as both citizens of their local community and citizens of the world. From Adam Smith and David Hume came the idea of the "civil" society, which taught us there was a space between the state and the individual, a public sphere that need not be dominated by markets and where people could come together in their own voluntary associations, from churches and trade unions to civic and municipal organisations.

Adam Smith thought that his lesser known book The Theory of Moral Sentiments, with its idea of mutual empathy, was a far more important contribution to our understanding of the world than his more famous tract against mercantilism, The Wealth of Nations. The idea of the helping hand mattered more to him than the invisible hand. And when the Scottish Enlightenment defined citizenship, it meant we were not just consumers or subjects but men and women with shared interests, common needs and mutual obligations to each other. It was an idea that not only inspired the modern study of sociology but underpins what we now call "social capital".

But up against the dislocation of the industrial revolution, ideas of citizenship had to change, as inspirational leaders appalled by the suffering of the new working class sought to transform a brutal economic free-for-all into a civilised society. Again Scots leaders played a major role. Having inherited a separate Scottish poor law, Scots could easily have argued for their own separate welfare state. But their leaders did the opposite: they led the UK in demanding the abolition of separate poor laws and their replacement by UK‑wide welfare institutions for pensions, healthcare, and help when unemployed, disabled and poor.

They were among the first to see that there were huge benefits to be gained from more than 50 million UK citizens pooling their risks and sharing their resources across nations. And so they evolved a new kind of citizenship that had influence way beyond Britain's shores: one that created for Scots, English, Welsh and Northern Irish alike the same rights to healthcare, education, welfare and minimum standards in the workplace. In doing so the UK became more than a single market for trade – it became the world's first social market economy.

By enlarging the very idea of freedom – delivering positive freedoms (the freedom to universal healthcare, education and social security) and not just negative freedoms – we redefined the idea of citizenship from one based just on civil and political rights in one nation to one based on civil political social and economic rights shared across nations. Even today no other group of nations – neither the EU, nor the states that make up the USA – has evolved such a sophisticated form of citizenship. The impact of the UK's achievement is striking. The median income of a family in Mississippi is around 60% that of a family in New Hampshire. The average income in Bulgaria, the poorest member of the EU, is about 9% of that of Luxembourg, the richest. Yet the income of a typical Scot is now on a par with that of his English neighbour. For in the 20th century at least, Scots found a way of living side by side with their neighbours in a multinational state, combining a strong sense of patriotic pride in Scots culture and our autonomous institutions with a willingness to cooperate in sharing the benefits of the whole UK.

But a new wave of globalisation has opened up new questions: not just about how a nation such as Scotland interacts with the multinational state that is the UK but how it finds its place in the world of McDonald's, Apple, Facebook and global financial markets. In such a world, economic opportunity and social welfare cannot be guaranteed, and citizenship cannot come alive as concrete, deliverable economic and social rights unless we manage globalisation effectively. What's underlying the recent wave of political nationalism is not Scots people's discovery of their Scottishness – Scots have always felt strongly Scottish – but the impact of global change on it. No less crucial is Scots' clear desire to hold on to their identity at a time when the previous upholders of it – from Scotland's distinctive churches, professions, civic authorities and even its sporting teams, who represented a cultural, apolitical nationalism – are in decline and have ceded their authority to speak for Scotland.

The economic transformation is well known: the Scots manufacturing and mining sector, which once led the world in shipbuilding, steel and railway construction, and which employed over 40% of Scottish workers, now employs just 8%. With many of the remaining manual jobs now viewed as lower skilled and worse paid than before, Scotland has been in a 50-year search for new skills, new jobs and a new prosperity. Its real quarrel is with globalisation, not with England.

And globalisation binds the world together in an intricate web of economic relationships – and changes our view of what it is to be a citizen yet again. As recently as 1990 international trade accounted for 20% of all world economic activity: now it is 35%. Soon trade between countries will account for the majority of economic activity. And so today, like every other country, Scotland is having to make its living in an economy so interdependent that 72% of all manufacturing input and 60% of all private sector economic activity are in non-Scottish hands. Once we include not just the employees of non-Scottish firms but firms wholly dependent on exporting into the global economy, two thirds of Scotland's private sector jobs – 1.4m – are bound up with trade that is dependent on our links with the UK and the wider world. And while the assets of British banks are five times the UK's national income, Scottish banks are more vulnerable to global capital flight, with assets 12 times Scotland's national income. Even if we were tempted to opt out, it makes no sense to sever, or even jeopardise, our connections with our biggest trading partners. As individual companies become ever more closely and irreversibly intertwined at a global level, there is no alternative to cooperation.

In years to come getting control of your economic destiny will involve new, more intense relationships with your neighbours, your geographical region, your continent and the wider world, and will inevitably mean layer on layer of cooperation with regional and global institutions, recognising that there are global problems – such as climate change, open trade and development – that need global solutions. One example suffices: no country can today secure its tax base without international cooperation to root out tax havens.

So a new idea of citizenship is emerging. It is not cosmopolitanism if that means that national loyalties do not matter. It is a citizenship that upholds national identities while recognising the benefits of shared sovereignty – the kind of citizenship Scottish people can understand: being Scottish, British, European and a citizen with connections with a world wider even than that. It is not abstract: it represents how people now live their lives – connected constantly through mobiles and the internet, able to communicate with anyone, in any part of the world, at any time – involving an identity that is, for individuals, more a matter of choice than at any time in history.

Of course it is not surprising that nationalism, once thought of as a creature of one time (the industrial revolution) and one set of circumstances (uneven growth and a response to the bewildering changes wrought by industrialisation) is re-emerging as a force to be reckoned with. It is, of course, people's sense of helplessness at what they see as an uncontrollable and unaccountable global economy that creates the conditions for nationalist movements. But the nationalist reworking of "small is beautiful" in the form of "small state sovereignty" gives us few answers to the question of how to navigate the global economy. Once the separatists argued that Scotland's future lay in "the arc of prosperity" from Scandinavia to Iceland to Ireland – a vision torpedoed in 2008. They now argue that small states are more flexible, adaptable and innovative than the old monoliths, and will be more competitive. But competitiveness also depends on your ability to deal with global financial markets and global companies, whose trade with each other dwarfs national economies. And the plain truth is that ability is greater for states with more heft.

So when I hear the Scottish finance minister, John Swinney, volunteering that Scotland might renege on its debts, a tactic used by Weimar Germany, and more recently by Argentina and Greece, I see the perils of the "stop the world I want to get off" philosophy of a narrow nationalism that fails to understand there is no hiding place for defaulters when borrowing in the international market. What has secured Scottish nationalism its greatest electoral successes is our frustrations with the insecurities and unfairness of globalisation. But, blinded by the dogma of the 19th-century nationalism of going it alone, the separatists are incapable of learning what I think Scots instinctively understand, that the response to the latest wave of globalisation cannot be to retreat into an exclusive sovereignty: the way forward is to share it.

So deep is their desire to separate from England that the nationalists cannot admit that most of Scotland's trade – 70% – and most of its jobs – 1m – are linked to our membership of the UK. What's more, the advantages of sharing to provide pensions, healthcare, welfare, defence and environmental protection will become more, not less, important in an interdependent world. So we should do nothing to diminish a UK citizenship that is grounded in shared social and economic rights. The challenge is to fashion a 21st-century citizenship founded not just on shared rights but on a sharing of sovereignty itself, one that respects national identities without losing the benefits of cooperation. After 18 September we should invite Scots to be part of a great unifying British project that can engage the whole of the UK: to evolve a new British constitution for the 21st century – one founded on diversity, and driven forward by a commitment to power-sharing, would engage not just MPs and councillors but the wider public. In my view it would move us as close as any country can be to a federal state when 85% of its people live in one nation.

The vote on 18 September could indeed be a moment of destiny, but not the one the separatists are praying for: one where a proud nation that wants to uphold its traditions and institutions in the face of the levelling effects of globalisation and the temptation to go it alone chooses instead to become a beacon to the world, a shining light for all countries seeking better ways of living side by side, and demonstrates that interdependence – a citizenship now driven by the will to cooperate with others – is a far bigger idea than independence.