History is, arguably, about continuity, but there are discontinuities, irreversible events which turn countries and civilisations before their due time.

Take, for example, the sudden and irreversible though predictable demise of Constantinople, taken down by the scimitars of the Ottomans, the last great assertion of Islamic power which finally ended before the gates of Vienna in 1685. 1685 could have been another irreversible event. Almost a thousand years before, what if the Muslim invader had won at Poitiers in 735?

What of Carthage, Nineveh, and many another ancient city, destroyed by invaders who tore down walls and buildings determined that none should rise again? The Sassanid empire, its borders and eminence taken over by Islam. ….

The slow demise of empires, most famously the Roman Empire, frontiers slowly eroded. Empires that had long sown their own seeds of destruction. We could add Christian Russia, or the Chinese empire under the Qing dynasty. ….

Countries, or, better, peoples, which we might consider blameless, who suffered in the backwash of history, Hungary, at Versailles in 1919, Greece post 1922. Hungary had the misfortune to be second string in a great and tired empire. Greece thought its moment had come, invaded Asia Minor, and reaped a whirlwind.

Greece’s was a catastrophic error of judgement. So too the British attempt to regain control of the Suez Canal in 1956. If any event symbolises the end of the British Empire, that was it.

And we have another, a very British category. Humdrum by comparison. We could argue a British speciality. Self-willed catastrophic errors of judgement. Misreading the current world order and our place in it, and misreading history, cocooned within notions of imperial sway and influence which simply are no more, failing to recognise that we operate today within spheres of influence, economic and political.

The current vehicle for such unwisdom – one could say stupidity – a referendum. Which by definition is irreversible. Maybe the greatest British contribution to the world has been reversibility. Policy has to persuade, cannot be implemented by diktat, can always be reversed. Compare Xi Jinping, Erdogan, Putin, all with their own imperial aspirations.

We gave to the world, and we now take away, by our own hand.