THE war over Gaza and Russia’s invasion of Ukraine are only the most violent of today’s world-shaping ­conflicts. US-China rivalry over Taiwan, Iranian defiance, Brazil’s “active non-alignment”, Brexit ­xenophobia … as the list of aggressive postures grows there is one grim sliver of intellectual satisfaction: Tom Nairn was right.

After his death in January this year, Nairn was described by then-first minister Nicola Sturgeon as “one of the greatest thinkers, ­political ­theorists and intellectuals that ­Scotland has ever produced”.

He was right when he argued that ­nationalism and ­nationality are not mere ­expressions of “­false consciousness”. They lie at the centre of modern ­history and are integral to what we call progress.

Writing in the 1970s, Nairn (below) called out the Marxist ­tradition that had initially inspired him. His ­comrades were wrong to see ­capitalism as an economic ­singularity.

The National:

In world terms, capitalism as a whole is a brawl of uneven ­development: it is driven by ­national competition overseen by nation-states. The price of the ­astonishing, ongoing development in human ­capacity and wellbeing, ­witnessed since the start of the Industrial ­Revolution, is dark reaction.

But haven’t we got a “get of jail free” card? Isn’t Scotland – and in a ­different way also England  blessed by having exceptional and ­long-lasting forms of national self-consciousness that are not “merely” nationalist? Don’t we have a “civilised” ­identity expressed by membership of our ­larger British union?

The idea that any of us can be “above” nationalism is deceptive. Nairn’s analysis showed why the influence of nationality is ­inescapable.

Take Scotland and the vote for ­Brexit, which was and is an overt ­effort to exercise a “British ­nationalism” in competition with the European Union’s. Sixty-two per cent of Scottish voters supported Remain – but more than a million fellow Scotspeople in Scotland backed Brexit. And there was only a 62% turnout.

READ MORE: What is the Supreme Court Rwanda case and the possible outcomes?

The combination of indifference plus support for Leave means Scotland cannot resile from responsibility for the result. After all, it was only a 1.3 million overall majority that imposed Brexit Britain on all of us in the UK.

Unionism is another form of ­nationalism, not its opposite.

In the case of the United ­Kingdom, it was historically a union defined by violent imperial expansion that joined Scotland, Wales and ­protestant ­Ireland to England in a shared, ­military and economic enterprise. We can’t look upon today’s hot and cold wars with a patronising sigh as if we too have not been perpetrators of implacable genocide and heedless expansion.

That seems a terrible thing to say if you believe, as I do, that we must ­support the Palestinians’ right to their homeland and a stop to the ­pitiless destruction of Gaza, while also ­supporting Ukraine to the hilt in its fight against Putin’s ­despicable ­invasion. Both are legitimate, ­democratic and rightful nationalisms.

Yet we cannot hide from the fact that they too are accompanied by their inhumanities. Nairn insisted on this in the essay in The Break-Up of Britain that became the starting point for all his later writing.

“Nationalism is always morally, politically, ­humanly ambiguous”. That is why he called it a “modern Janus”, after the Roman god of doorways that looks back into the past as well as forward towards the future, two faces carved into a single body.

READ MORE: Labour MSPs back Holyrood Gaza ceasefire call from Greens

Zionist nationalism looks towards the Old Testament; Putin’s nationalism towards Czarist grandeur; ­Iranian fundamentalism to the ­prophetic origin of Islam; China to its rightful place as the Middle Kingdom; the US to remaining paramount. All also strive to be as modern as possible, not least in the means they deploy to ­resurrect the past.

There is no escape from the ­dilemma. But to understand it we have to realise that the baleful desire for revenge stems from the world’s system.

Every nationalism presents ­itself as its own historic source. Whereas, in fact, as Nairn put it, it is the forest that creates the trees. If we want to break from the ­regressive, violent mobilisations of nationality, we have to recognise this can only be achieved jointly. It can’t be done “alone”.

The National:

This is obviously so in the ­Middle East, where extreme Zionism and ­Hamas are symbiotically related. It applies to all the conflicts of our time. The way out is via mutual ­co-operation and peaceful ­competition that ­tolerates difference.

A successful Yes to Scottish independence needs a successful Yes in England to the abandonment of the Westminster Empire State that it will entail. There was a chance of this ­after 1997, when the first Labour ­government of our era ­implemented “­constitutional change not ­experienced for ­centuries”, in the words of the Law Lord, Tony ­Bingham.

The Human Rights Act, freedom of information, the abolition of most ­hereditary legislators, and above all the termination of Westminster’s ­monopoly with new parliaments in Scotland and Wales … the direction of travel was unmistakable.

Britain was heading towards a European-style “new constitutional settlement” that would give each nation equal political status despite England’s greater size.

Had this happened, the UK might have escaped from its imperial ­mortmain – so that today we might have felt at home in the EU with our member nations at ease with each other.

There is nothing more dangerous than a road half-taken. By ­embracing the US rather than the EU, most ­decisively with the Iraq War, Blair reversed the promise of his domestic reforms.

READ MORE: Planned law change risks 'criminalising fans singing Flower of Scotland'

“Our ambition is big, to construct a global agenda around which we can unite the world, rather than ­dividing it into rival centres of power,” he wrote to then-US president George W Bush, a week after the launch of the “Shock and Awe” assault upon Baghdad.

The imperial pretension is ­unmistakable. Brexit began then with Britain’s support for Operation Iraqi Freedom – in three ways. First, thanks to its embrace of Washington rather than Paris and Berlin; second, because of the invasion’s ­humiliating failure; and third, thanks to the ­refusal, even in defeat, to recognise the need to change and instead cling to big, indeed bloated, ambition.

The outcome is a Brexit that has manacled Britishness forever to a ­regressive Thatcherite desire to prove to the world that “we have not changed”. That’s only the ­consequence for us. The madness of the invasion of Iraq started what Paul Rogers predicted in 2003 would be a “30 years war”. Our country bears a direct responsibility for today’s arc of conflicts.

The lesson?

We too need to seek peace with others. This means that our priority is to return to the space in which our ­European nations can thrive in peace. Namely the European Union, not the British one.

The EU is far from perfect, of course. There is never an escape from ambiguity.

But Europe has saved the nations of Europe. It replaces our history of mutually destructive hatred with contested consent. It needs to be the common destination of the UK’s ­nations. Perhaps it is only by acting together in a joint liberation from the Westminster state that the nations of the UK can free ourselves from our shared imperial legacy.

Anthony Barnett is the co-founder of openDemocracy. He chairs the Break-up of Britain Conference Steering Group and is a supporter of Europe for Scotland