The English and Welsh voted to leave the EU. They are entitled to leave the EU, and it is not the job of the leader of the Scottish National Party to frustrate their intention, or even try to influence the terms on which the English and Welsh leave the EU. Just as it is not the job of the Scottish National Party to stop Westminster having the Tory governments the English people inexplicably keep voting for.

It is the job of the leader of the Scottish National Party to secure Independence for Scotland, and to ensure that the vote of the Scottish people, to remain within the EU, is respected. I am therefore entirely unconvinced that for Nicola Sturgeon to try to play a role as the darling of the Remainer population of England is of any use to the people of Scotland. And the truth is that knowing the very last detail of the eventual Brexit outcome, of which we know the essential outlines, will have virtually no effect on the prospects of an Independent Scotland.

Now is the moment of maximum chaos; whatever eventually emerges between London and Brussels will work without immediate catastrophic effects. People will not starve and run out of medicine, in the real world. The UK will continue to be a Tory hell with some changes of arrangements. Scotland should not be in Tory Hell, whatever Tory Hell’s relationship with the EU.

I am here considering Brexit only as it affects Independence.

If Independence is actually Sturgeon’s overriding aim, the only logical analysis on her part which I can see, that explains her constant haver on Indy, is that Brexit will be so immediately catastrophic as to have Scots clamouring for Independence as an alternative.

But that is a miscalculation. I am confident the dislocation effects of Brexit will not be as immediately harsh as doom-mongers predict. Plus if the outcome were immediately harsh, Scottish Unionists are far more likely to don tin helmets and rally round the Union Jack while blaming Johnny Foreigner, than they are to convert to Independence on the grounds the UK is having a hard time.

There are of course other options. The UK may not leave the EU at all – which would do nothing to advance the cause of Scottish Independence. There may be a general election which could bring Labour into power – that would on balance reduce the desire for Independence in Scotland.

The truth is, that the delay in pushing for Scottish Independence is not predicated on increasing the chances of attaining Independence. It is based on attempting to secure for the United Kingdom what is best for the people of the United Kingdom. It is an essentially unionist position.

This is Sturgeon’s dilemma. She sees a UK in which the tragedy of the Remain camp is that its leadership is utterly discredited. Blair, Campbell, Umunna, Clegg, Mandelson, Straw; the only people articulating a Remain position have no credibility. They are all people who turn the nation’s stomach when they show up on Marr. That leaves a huge leadership vacuum which Sturgeon is filling in Remainer eyes, and in Guardian/BBC eyes. A Remain minded leader who is not personally hated. A very rare thing indeed.

Who else do the Remain camp have as a leading politician who is not discredited and deeply unpopular? Serious question, please do attempt an answer.

That is a massive temptation to a politician to step forward and take the glory. If Sturgeon appears far more interested in Brexit and in Remain than in Scottish Independence that is, on a human level, very understandable. If it leads to the great opportunity for Scottish Independence being passed over while in pursuit of UK/EU relations and fawning headlines in the Guardian, that would be nonetheless unforgivable.

The largest battle of the Jacobite 45 was not Culloden and not Prestonpans but Falkirk. On 17 January 1746, amidst a howling winter storm, an 8,000 strong Jacobite army routed a similar sized Hanoverian force under Lieutenant General Hawley, which had been marching to the relief of Stirling Castle. By every conventional measure it was a Jacobite victory. They held the battlefield while the Hanoverians retreated pell-mell to Edinburgh, they captured the Hanoverian artillery and baggage, Hanoverian casualties were higher by about four to one. Yet the history books tend to call it a draw.

The Hanoverian force broken at Falkirk formed 80% of the victorious force at Culloden a few months later. Falkirk was decisive because, had the Jacobites chased Hawley’s force as it retreated to Edinburgh in great disorder and with shattered morale, it could have been destroyed. This did not happen, for a variety of reasons. The most important was that Charles Stuart thought it prudent to get all his ducks in the row by capturing Stirling Castle first. The second was that Charles had failed to appoint an overall commander or a commander of the left wing, and spent the actual battle with his senior staff indoors around a fire staying out of the storm, while George Murray, fighting on foot, led the right wing of MacDonalds and Athollmen to victory.

You will gather that the research for my biography of George Murray continues. But unless you are particularly slow today, you will gather that I see a lesson here for the Yes Movement.

This is our Falkirk moment. Both the Tories and Labour are riven by internal dissent over Brexit. The UK is in palpable political chaos, and the prospect of remaining tied to Westminster has never been less appealing. It is not the job of the SNP to “save the UK from a bad Brexit”. It is the job of the SNP to win Scottish Independence, after which Scotland can decide itself on whether it wants to be in the EU or not (and the fact is that when last asked it very much did).

I fumed when the SNP fought the last Westminster election on a “don’t mention Independence” platform, and deservedly lost MPs as a result. I fumed still more when I was not allowed to hold a fringe meeting on Indyref2 at the SNP conference, and the subject was rigorously excluded from the motions before the Conference itself. Now that Nicola Sturgeon is daily putting further and further excuses forward for not moving on Independence, I am inclined to fear that the comfortable fire around which Charles Stuart warmed himself during the Battle of Falkirk, is an apt analogy for the position of the SNP Establishment, who are doing very nicely, thank you, out of their position within the UK, and show no inclination whatsoever to stop warming their toes at the Establishment hearth and move out into the storm and bullets.

I have no more claim to be a strategic genius than the next man. But when I see my sworn opponents, disoriented, in disarray, and fighting fiercely amongst themselves, I cannot help but feel that now is the time to attack them.