“When the facts change, I change my mind,” John Maynard Keynes is reputed to have remarked, “what do you do, Sir?”

That the legendary economist most likely never uttered those words doesn’t really matter, for it captured the pragmatism required of seismic changes to the status quo, be they political, economic or constitutional.

And that’s where we are a few days after the EU referendum, grappling with the biggest crisis in the UK since the Second World War. Normally that sentence would epitomise journalistic hyperbole, but not now. When I asked one shrewd observer of the political scene to summarise the situation, he replied: “It’s a complete cluster-f***”

Politicians, however, have to play the hand they’re dealt, which is why Nicola Sturgeon has emerged over the last few days as the only figure in the UK actually on the front foot. Drawing on all her considerable strengths, she more than anyone else has found the right words since Friday morning, but then that’s the easy part.

The First Minister has been admirably frank. She doesn’t have all the answers; she doesn’t know how things will pan out (no one does); this constitutional cluster-f*** is not of her making, but it falls to her and the Scottish Government to chart a course. The SNP leader senses there’s a great political moment to grasp, but at the same time she’s responding to events rather than controlling them.

Ms Sturgeon undoubtedly has a mandate to hold another referendum given the wording of the recent SNP manifesto; “material change” has come to pass, and judging by polling over the weekend the necessary shift in public opinion might also be in play. But talk of a “surge” in support is premature, these are heady days and what feels right now might not once temperatures cool and the political terrain becomes clearer.

The First Minister says she’s exploring all available options, but I can’t help feeling these are more limited than at first appear. And having flown the referendum kite on Friday morning she’ll find it difficult to pull it back down again, although it was striking that by yesterday morning she was making it repeatedly clear that this particular “option” was not her “starting point” but a last resort.

Within the SNP, there appear to be some who want to move quickly, perhaps by the end of this year, and those who see 2018 as more realistic and, of course, winnable target date. Alex Salmond, one suspects, is in the former camp and Ms Sturgeon in the latter, indeed yesterday the First Minister said it would be absolutely “essential” to hold another referendum within that Brexit “timescale”, i.e. before the UK formally withdraws from the European Union, perhaps in early 2019.

What of the other “options”? Talk of Scotland somehow doing a “reverse Greenland” is superficially attractive but seems unlikely to be a runner in practice, while yesterday the First Minster also raised the prospect of Holyrood somehow “vetoing” Brexit, but that isn’t a credible position. Remaining within the Single Market does not, of course, necessarily mean remaining part of the EU, thus membership of the European Economic Area (which includes Norway and Iceland) might also be on the table.

But it all depends whether Brussels is up for responding pragmatically now “the facts” have changed. They might well be, certainly more so than in 2014, but equally they might not. The signals so far have been mixed, but even should the political will manifest itself there are the usual stumbling blocks, not least the prospect of a Spanish veto. Soon Ms Sturgeon will begin the necessary charm offensive with 27 Member States, but it might not be met with unanimous approval.

If, however, some sort of deal emerges, it would provide the First Minister with much-needed political cover going into a second referendum, the ideal scenario framing an independent (or semi-independent) Scotland as a sort of safe haven for businesses and EU citizens relocating from London or the north of England. Even then, the currency and border questions are not easily answered, but if Ms Sturgeon can pull that off, independence would be virtually guaranteed.

The choice would be much starker than it was in 2014: either some semblance of stability via “independence in Europe” or a dysfunctional Britain. Now there’s no denying that the facts of the Unionist case have changed – despite Boris Johnson’s bizarre claim that Brexit doesn’t mean the UK “will be in any way less united” – but the SNP leader seriously overstated the case by claiming the UK as we knew it did “not exist any more”.

Nor does the case for independence as articulated in 2014. Scotland is currently a (significant) net beneficiary from the status quo, while as a newly-independent member of the EU it’d most likely be a net contributor, a reality than cannot be reconciled with a vision of independence predicated on consistent levels of public spending and low taxes. The First Minister has previously spoken of pitching independence in a more “realistic” way; well, now’s her chance.

But will she take it? There’s been a tonal shift, certainly, an acknowledgement of the obvious complexities involved, but that isn’t adequate. Any “reframed Scottish independence case” (as Richard Lochhead called it on Twitter) would have to acknowledge that almost everyone would take a financial hit, at least initially. David Cameron’s threatened “punishment Budget” might have crumbled into dust, but something similar would certainly be necessary in post-independence Scotland.

Over the last few days Brexiters have swiftly ditched most of what they promised before last Thursday: apparently leaving the EU no longer necessarily means more money for the NHS, fewer migrants or an end to freedom of movement. But had Scotland voted Yes in September 2014 it would’ve been Nicola Sturgeon and Alex Salmond who’d have been forced to admit that most of what they’d set out in the White Paper was undeliverable. Then too, Project Fear would quickly have become Project Fact.

Yesterday the First Minister promised “an honest conversation every step of the way”, and let’s hope that’s true, for it’s no longer sustainable to gloss over difficult facts with finely-honed debating points. There are also huge capacity issues within both the SNP and Scottish Government when it comes to macro-economics, trade and so on. “Every practical problem is capable of solution,” was Kevin Pringle’s breezy assertion in his Sunday newspaper column, but he didn’t go on to offer any.

From the SNP’s point of view, it might now be the case that none of this is a problem. The party’s existentialists will support anything if it means independence, while its utililitarians may look at the UK and conclude they have little choice. Besides, a majority of British voters just stuck up two fingers at facts, as did 45 per cent of Scots nearly two years ago. In a post-factual political environment minds can be changed regardless, and independence becomes eminently more achievable.