JOHN was a family neighbour. Every year, when the bells Hogmanay chimed, he would appear at his upstairs window. As couples kissed, Catherine wheels spun out the last of their light and Jackie Bird feigned taut good cheer on the telly, John would haul open the sash, grinning, a malt in hand. Every year, his house would exhale the old year into the upper atmosphere, letting the new year breeze through. John’s gone now, sadly, but it was a small yet reliable ritual of the street – and a compelling one.

For independence supporters, John’s blast of fresh air may feel welcome this January. It was a stale political year for Scottish nationalists in 2017. One of the pleasures and pains of the turn of the seasons is how it forces you to cast a weather eye backwards and forwards. In the thick of things, you don’t think of opportunities you have taken and missed. You can barely see all the roads more – or less – travelled for all the trees.

But grisly and dispiriting though it might have been, 2017 carried critical lessons for independence supporters – if we’re prepared to learn them. As Brexit grinds painfully on, as Her Majesty’s Government continues to shed layer after layer of its credibility, as unfunny grotesques like Toby Young cash in, as Tory splits expand into caverns and as Labour bumbles affably off the Brexit cliff, the case for Scottish independence has not advanced one inch. Some brisk housekeeping towards the end of the year suggests the Holyrood government has recovered its political mojo – but Nicola Sturgeon’s administration enters a new political year of dramatic volatility.

READ MORE: Scots NHS copes with flu surge – as May apologises for crisis in England

The SNP cannot predict the future. The party can only guess whether Brexit will generate a material change in a majority of the population’s attitude to independence or fizzle into a damp squib. But what they can do is take steps to ensure that – come what may – they have the intellectual heft behind their arguments. They can take the tough business of statecraft seriously.

Brexit has given us a brutal object lesson in what halfwit constitutional change looks like. This ought to be a sobering experience. If the irresponsibility of this Bash Street Kids government sticks in your craw, if David Davis’s chortling lack of detail offends you, if Boris Johnson’s crayon plan to Make Britain Great Again disturbs you, if you think that political leadership of this kind is a contradiction in terms, then there’s a material responsibility for proponents of Scottish independence to make a better job of it. And yes, that involves excavating the ruins of the 2014 campaign and the losing coalition it mobilised.

The political problems generated by Brexit are not unique to the Westminster parties – they strike directly at the heart of the indy prospectus put to the Scottish people in 2014. Emphasising recasting old relationships in newer, healthier forms, the upbeat 2014 vision was premised on the idea that both an independent Scotland and the remainder of the UK would remain European member states. The campaign used a gentle vocabulary of co-operation, shared institutions and currencies, and surly lodgers replaced by good neighbours. It ignored inconvenient power asymmetries.

Whatever its economic merits, 2014’s currency position handed George Osborne a loaded revolver and said “please don’t shoot me with this”. Auld sentimentalist that Caligula was, the chancellor pulled the trigger. 2017 ought also to have taught us that assuming your negotiating partner is rational – coolly maximising opportunities for shared gains and minimising mutual losses – is problematic when your partner is captured by addled and self-defeating nostalgia. Just ask the Irish. Brexit knocks all these pillars through. Still missing from the public discussion is any real reflection on the implications of these changes. Conceiving independence as an easy lifeboat away from this disaster is a slogan – not a policy.

Some of you may shrug, and be tempted to snarl “detail”. Since 2014, there has been some debate in pro-indy circles about whether the 2014 White Paper was a political blunder. To carry a political campaign, the logic runs, a slogan which resonates will do. Get a bus. Slap a big number on it and pledge to spend it on likeable public sector workers. It worked for Gove and Johnson, after all.

By rolling out divisive detail about Scotland’s constitutional future, some argue, the Scottish Government sowed disagreement within its supporters while giving Better Together a moveable feast of piddling details on which to prey. This helped frame the referendum campaign in terms of pounds, borders and petty regulations, rather than the overarching idea that independence allows you to take these choices for yourself, whether you are a socialist, a social democrat, a social conservative, or a classical liberal.

Learn the lessons of 2016, proponents of this perspective say. The Leave campaign didn’t scratch out a 670-page suicide note to win 17,410,742 votes and carry Britain out of the EU. It found a majority of people where they were, politically and socially. It structured their anxieties, explained their perceptions in psychologically convenient ways. They built their campaign on a sound bedrock of tabloid propaganda about joblessness, resources and immigration. They didn’t invite the British people to reconceptualise their politics – just to act logically on the world-view outlets such as the Daily Mail and the Express have cultivated for decades. Leave Britain communicated both in dog-whistles and bright, clear, emotional notes. Against this backdrop, the result was not just emotionally explicable, but predictable.

There is something to this. Approaching political decision-making as bloodlessly rational ignores the human factor and the weight of experience which tells us that we reach decisions first, and find our reasons later. To campaign is not to govern; winning independence is not the same as building a new state. Recognising the difference, however, does not mean that state-building should be the junior partner to spin.

There was always a tension in the SNP’s Westminster project after 2015. With Jeremy Corbyn flailing around the chamber with a thousand knives in his back, you can see the logic of Angus Robertson’s position: “We’ll be a real opposition in Westminster.” We’ll be bonnie fechters, haunting every committee, dishing out drubbings at every Westminster Hall debate. There will be kind words said in the TV studios about our personal merits and viral Youtube videos will rip through social media. We’ll underscore that the outgoing Scottish Labour blob were idle, nae-users. We’ll be vigorous, oppositional, judiciously bolshy.

There was much to commend in this approach – but the core of its thinking was dead wrong. There was an old (and slightly cruel) joke in some Nationalist circles that come Independence Day, Angus Robertson would be found weeping, tweeded and chained to gates of the Palace of Westminster. Behind the gag was a suspicion – or at least, an anxiety – about the dangers of becoming institutionalised and losing the place.

Think of the sad epitaph of every radical socialist who seamlessly graduates to ermine, subsidised carp for luncheon and a peerage: “I entered politics to change the institution, but the institution changed me.”

If the last year taught us anything, it is that Westminster is a dead space for Scottish national politics. Speak in as many debates as you like, march through the lobbies night after night – nothing can be achieved against the wall of the UK Government’s indifference.

Nationalist MPs can howl against the injustices which Theresa May’s undead administration continues to inflict on the people of this country. They can indict her ministers, catch them in their contradictions, press them for detail, and strip away the atom-thin veneer of credibility which sustains the brittle shell of her administration. They can represent their constituents with diligence and care. But Nationalists can never be the “real opposition” in Westminster. What they can do, however, as the cold wind of the New Year surges through the empty palace, is plan. Plan, and avoid making their opponents’ mistakes.