SOMETIMES societies and states face challenges that overwhelm them. These existential threats may come from within or without; and are often linked. The Roman empire eventually capitulated to the Visigoths, but only after it had been fatally wounded by internal divisions.

Likewise, the empire of the Incas succumbed to a small group of Spanish adventurers, who took full advantage of the internal conflict brought about by rivalry for Inca kingship.

History is littered with similar examples of empires and states that appeared invincible only to experience rapid and fatal collapse.

In his book Collapse, Jared Diamond, teases out five main reasons why this happens. In looking over his five-point framework below, think about how closely these relate to the multiple crises facing the UK right now. And consider the consequences for the Union if it fails to meet these challengers, as seems very likely.

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To illustrate his five-point framework Diamond uses the example of the Greenland Norse. A substantial society of Norse people who settled in Greenland, and whose society collapsed owing to circumstances that may have been within their control.

The first item on Diamond’s framework is to look for human impacts on the environment: people inadvertently destroying the resource base on which they depend. In the case of the Viking Norse, the Vikings inadvertently caused soil erosion and deforestation, which was a particular problem for them because they required forests to make charcoal, to make iron. So, they ended up an Iron Age European society, virtually unable to make their own iron.

A second item on his checklist is climate change. Climate can get warmer or colder or dryer or wetter. In the case of the Vikings -- in Greenland, the climate got colder in the late 1300s, and especially in the 1400s. But a cold climate isn’t necessarily fatal because the Inuit -- the Eskimos inhabiting Greenland at the same time -- did better, rather than worse, with cold climates. So why didn’t the Greenland Norse as well?

The third thing on his list is relations with friendly societies that may prop up that society. And Diamond says that if that friendly support is whipped away that makes the society more prone to collapse. In the case of the Greenland Norse, they had trade with the mother country -- Norway -- and that trade dwindled: partly because Norway got weaker, partly because of sea ice between Greenland and Norway.

The fourth item on his checklist is relations with hostile societies. In the case of Norse Greenland, the hostiles were the Inuit -- the Eskimos sharing Greenland -- with whom the Norse got off to bad relationships. And we know that the Inuit killed the Norse and, probably of greater importance, may have blocked access to the outer fjords, on which the Norse depended for seals at a critical time of the year.

And then finally, the fifth item on his checklist is the political, economic, social and cultural factors in the society that make it more or less likely that the society will perceive and solve its environmental problems. In the case of the Greenland Norse, cultural factors that made it difficult for them to solve their problems were: their commitments to a society investing heavily in cathedrals; their being a competitive chief-led society; and their scorn for the Inuit, from whom they refused to learn.

Now compare the missteps the UK has made and how closely these relate to Diamond’s framework for collapse. First the environment, the UK is way behind others and according to The Times newspaper, its cities remain clogged with polluted air.

Second, the UK has made a very poor attempt at climate control. And is even prepared to sacrifice these tiny gestures for a trade deal with Australia.

Third, the UK picks fights with its once-friendly neighbours almost weekly, if not daily. Any goodwill that did exist is being steadily eroded.

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Fourth, the British government is obsessive about finding new hostiles. It picks fights with China, for example, then pleads with them to supply nuclear power plants. Then, it jumps into bed with the US and Australia to threaten Chinese interests in the far east.

Fifth, its obsession with awarding very lucrative contracts to supporters has alienated the rest of society who must pay for these goodies. Without agreed values and ethics, no society can survive.

The lessons of history are clear and irrefutable, the UK is headed for collapse, regardless of what Scotland decides. Scots, therefore, have a clear choice. Stay and suffer the consequences of this impending collapse. Or quit. Now.

Philosopher, A C Grayling, is our next guest on the TNT show. Joins us at 7pm on Wednesday on IndyLive