THERE are “tipping points” in politics.

These are moments when, after a long build-up of pressure, the impossible suddenly becomes the inevitable.

Sure-footed politicians respond adroitly to these tipping points and adjust their stance accordingly.

Wise politicians anticipate them. They move in advance and prepare the new ground to their own advantage.

By the 1980s apartheid in South Africa was becoming unsustainable economically as well as morally.

It was clear that its days were numbered.

Yet many white South Africans – even those who had moral qualms about apartheid – had a genuine fear of what might come next.

They were terrified of a violent take-over by a Mugabe-style revolutionary movement, which would have driven the farmers off the land, confiscated property and set up an authoritarian populist state.

In such a country, with a worthless currency, empty fields turning to dust, and all the mineral wealth squandered, there would have been no place, and no future, for them.

Some responded to this dreadful prospect by digging their heels in. The wise, however, realised that by moving in advance of the tipping point being reached, they could help guide the process and avoid, or at least greatly mitigate, the outcome they feared.

Under the leadership of FW de Klerk, the National Party – the main party of white rule which had been in power since 1948 – pivoted its long-standing position. Instead of sustaining apartheid, it set out to control its dismantling.

Nelson Mandela was freed. The ANC was legalised. The “Truth and Reconciliation” process was initiated. Negotiations took place. The process for constitutional change – to build a ‘Rainbow Nation’ of multiracial democracy – was agreed.

Many Scottish Conservative voters no doubt feel a similar fear at the prospect of Scottish independence. In the run-up to the 2015 referendum, images were circulated in the anti-independence press of Alex Salmond’s face on future Scottish coins. Although made partly in jest, these images were a splendid piece of propaganda because they stoked two very real fears in the hearts of No voters.

The first was a fear about the distribution of power in the new Scottish state. Would it be a one-party regime of the SNP? What scope or space would there be for those who dislike the SNP? Would they be driven out? Would an independent Scotland still have political room for them?

The second was a fear of the loss of economic stability. The question of “what currency shall we use” was really a code for “will our money – our savings, investments, property – be worth anything, or will we lose it all?”

While those of us on the pro-independence side envisage Scotland as a sort of Norway-in-waiting, our opponents have darker imaginations.

They see a “separate Scotland” as a sort of proto-Cuba, Venezuela (pictured) or Zimbabwe (or, best case scenario, “Greece without the sunshine”). These fears persuaded 55% of the voters that they were better off with the devil they knew.

Faced with such a disastrous prospect, sensible, pragmatic, prudent conservatives should at least be working on a contingency plan – one that could prevent their worst fears being realised if the next referendum does not go their way.

They should be looking ahead, beyond the tipping-point of independence, to consider their plans for a Scottish state they can live with.

Just as the white leadership insisted on property rights and minority protections in the constitution of South Africa, so the moderate Tories in Scotland should insist on the kind of democratic mechanisms, written into the fundamental law of the future Scottish state, that will help stop any “Scottish Mugabe”.

There might even be room for compromise: agreeing not to stand in the way of independence in exchange for certain constitutional concessions.

After all, it is in no-one’s interests for Scotland to become a failed state, and it’s better to yield and compromise than fight it and loose.

If independence means the bottom falls out of the Scottish Conservative and Unionist world, at least the constitution could offer them a softer landing.

As a minority party, they have a stake in keeping proportional representation.

On issues such as property rights, the monarchy, and religion-state relations, there are specific Conservative perspectives to be argued for.

Some on the left might resist this, but real-life constitutions that work and endure are based on negotiation and compromise. They represent the common ground of democracy, the basic rules and principles which are generally acceptable across partisan divides.

Besides, it is a matter of principle. Conservatives are part of the nation and should – for their own sakes and for the sake the stability and resilience of Scottish democracy as a whole – also be part of the constitution-building process.

Now, which brave Scottish Tory will be first to open that constitutional conversation?

This column welcomes questions from readers