Beyond vague slogans and nostalgic evocation of bygone glories, Brexiteers have always struggled to articulate a coherent vision of Britain's place in the world once it leaves the European Union.
What they do know is that the US will loom large in that post-Brexit future. Once free of the regulatory shackles of Europe, the thinking goes, Britain can renew the special relationship, turning definitively to its more natural ally across the Atlantic as a partner in trade and diplomacy.
What the Brexiteers tend not to acknowledge is that the world has changed since the 2016 referendum. To see how this affects their project, they need only have looked at the unfolding crisis in northern Syria this week. Under Donald Trump, US alliances have been rendered void.
The Kurds, the US's most reliable ally in its fight against Islamic State, have discovered in the most terrible circumstances that their close involvement with the Americans on the battlefield ultimately counts for nothing. It's a lesson that South Korea, Japan, Germany and several other Nato states have already had to absorb. In other words, Britain is pinning its hopes on a partner who has never been less trustworthy.
To this, a Brexiteer would no doubt respond with that Theresa May-era coinage: Global Britain. What London envisages is not merely a reorientation towards America but a much broader expansion of its foreign relationships.
For decades, London has channelled its political influence on the continent largely through the EU
This was a useful Tory branding exercise during and after the referendum, reinforcing its message of a swashbuckling power triumphantly re-emerging on to the world stage, but it was fundamentally a defensive spin designed to dress up a retreat as an advance, a closing in as an opening up. In the coming months and years its contradictions will become painfully apparent.
The idea of Brexit as an internationalist project is absurd. Those most naturally inclined to buy into those outward-looking ideals – young, well-educated urban voters – were the least likely to vote for Brexit and are among the most disillusioned by the direction their country has taken since 2016.
In the Brexiteer heartlands, conversely, polls show widespread mistrust of globalisation, wariness towards immigration and more interest in 19th century fantasies of national self-sufficiency than in the collaboration and multilateral cooperation a meaningful global agenda in today's world would imply. Theresa May embodied the paradox.
One day, she would speak of Britain’s cosmopolitan credentials, the strength it drew from its diversity and its openness to the world. The next she would say, as she did at the first Conservative conference after the referendum, “if you believe you are a citizen of the world, you are a citizen of nowhere”.
A real Global Britain would have to make trade-offs, but whether a country driven by a radicalised Conservative Party captured by single-issue extremists and constantly looking over its shoulder at the Faragist fringe is capable of that is an open question.
Is the UK willing to increase its overseas aid budget? Is it prepared to liberalise its visa schemes for, say, migrants from the Indian subcontinent? These are the compromises that tend to get bundled into free trade agreements. Three years have passed since the referendum, yet neither May nor her successor, Boris Johnson, has done anything to prepare the country for the trade-offs that lie ahead.
Ireland's response – embracing co-operation, pooling sovereignty, opening up – is the polar opposite
Nor have they done much to revive a diplomatic network that had been neglected even before the referendum. The problem is particularly acute in a region that hardly figures in the Global Britain agenda, but one where London is going to have to work hardest to establish itself after Brexit: Europe.
For decades, London has channelled its political influence on the continent largely through the EU. But as it grew increasingly semi-detached, that influence waned, its standing suffered and it ceded leadership on key issues to France and Germany in particular.
As Brexiteers are often reminded, the EU is Britain's biggest trading partner. But the years since 2016 have underlined starkly how closely the UK cleaves to Europe on political and strategic questions as well. On everything from Iran and Russia to climate change and Middle East policy, London is in the European policy mainstream – and sharply at odds with Washington.
When Britain looked for solidarity after the assassination of Sergei Skripal in Salisbury, it found it in Europe. When it wanted a maritime alliance earlier this year to protect commercial ships in the Strait of Hormuz, it turned to Europe. When it prioritised stopping piracy in the Horn of Africa, it joined a combined EU naval operation.
As Johnson pointed out this week, the UK is leaving the EU, not Europe. But it is about to leave the main political-economic club on the continent without any broader strategy as to how it will manage its relationship with that organisation or define a new role for itself in a region where its influence is already fast diminishing.
The UK’s problem – how to remain influential and relevant in a world of rising powers – is shared by many small and medium-sized states. Its counter-intuitive response is to sever its most important alliance and go it alone. Ireland’s response – embracing cooperation, pooling sovereignty, opening up – is the polar opposite. After this week, it’s not hard to conclude which one looks the safer bet.