The surprising thing about seismic shifts is that there's normally quite a lot of warning beforehand - it's just we don't recognise it or understand what it means. We wait for that last moment, until we can feel the tremors and hear the subterranean rumbling that indicates the ground is about to shift beneath our feet.

In retrospect it's easy to see how we ignored all those warning signs. Anything that didn't fit our assumption of normality, the way the world worked, was simply dismissed as a "black swan" moment - exceptions proving the rule. It's only when we look back that we realise how those events fitted together and what they meant. Then it all makes sense and we realise we could always see the contours of this long, slow, shift, it's just that we didn't want to recognise what was happening because it was all too hard. Then, eventually, the last piece clicks into place, the jigsaw is revealed, and we have to accept reality.

This is the only way we can interpret what's happening in America today.

Don't get me wrong - the US remains the world's only real superpower. It is indispensable and it's going nowhere, no matter how much President Trump would like to simply drift off into space, untethered from reality. But America is not what it was at the turn of the millennium, just 20 short years ago.

At that time its economy offered a model everyone could seek to emulate and its cultural product was dominant around the globe. But what was far more significant was the way its society shone so brightly. It seemed to be a model for us all, showing us how to get things done, achieve, and live a better life.

Then things began to fall apart.

It would all be so much simpler to explain if there was a single reason for what's happened, but there wasn't. The attacks of September 11, 2001 revealed a vulnerability but also incredible strength. The US shrugged off the trauma and, utterly supported by the world, quickly destroyed al-Qaeda's base. But that was when, militarily, things began to go wrong. Washington had flexed its muscles and decided it enjoyed using them. Unfortunately it was to find in Iraq that creating an enduring peace is much harder than gaining success in war, and so the also dragged on. Aiming for an objective that could never be accomplished given the resources to hand meant that every success was illusory and so a quagmire developed, slowly bleeding resources but, far more importantly effort and energy that needed to be focused elsewhere.

Then, in 2007 the bursting of a minor, sub-prime house lending bubble escalated to engulf the world financial system. The economic model that had seemed so sound was revealed - just like the military - to have flaws so deep they couldn't just be pasted over.

Yes, the economy recovered but the gulf between rich and poor widened. Much more importantly, it had become obvious the American dream, of shifting from poverty to wealth, wasn't actually available to everyone because people who were poor, or black, realised they would be forever locked out of the gilded cages where life was so good.

By 2009 the nation was led by its first-ever black president, a man who seemed to promise a new way of engaging with the future. In fact nothing changed. By the time Barack Obama left office it was obvious the 'hope' that fuelled his election campaign was empty; all that noise and clamour he had created was nothing more than the reverberating of an empty can being banged by a stick. The failure of Bernie Sanders campaign simply revealed the Democrats didn't really want change. They were happy with Hillary Clinton's offering, finessing the detail around the edges but no change to the status quo. But the electorate was angry and that's why Trump won power.

His victory set the stage for the current, two-act tragedy. It begins with the bluster and incompetence that allowed coronavirus to spread throughout the country, the most powerful nation in the world brought to a standstill by a virus no one was prepared to do anything about. It's deadliness had been revealed but the administration ignored the threat and then, when the danger was revealed, blamed everyone else for the pandemic.

Society has become detached from the truth, as was revealed when Facebook insisted it could not be the arbiter of fact. Instead this so-called 'social' medium fostered whatever belief-systems people chose to share until the really wacky had become normalised and the rational centre began dissolving. And then a small incident occurred.

That event's not even classed as a murder - after all, the victim was black and the foot that choked out his life was white, belonging to a police officer. The flames and the violence spreading through the country will, eventually, be extinguished. What won't be is the grievance and anger now bubbling so close to the surface it threatens to engulf society in a conflagration.

A successful, harmonious society doesn't need to call out the National Guard to put down riots and protests.

Something is very wrong: hunting for the usual suspects won't reveal the problem. That's because it's buried too deep within the very fabric of American society itself. The country that offered, once, our guiding light has been dimming for a long time. By the time coronavirus is over, we will look elsewhere for role models.