Has Boris Johnson made a breakthrough in the Brexit talks? That’s the impression you’d get from reading this most of this morning’s papers, which all major on Angela Merkel’s comment that an exit from the backstop could be found in 30 days.

But Merkel is neither suggesting that there is about to be a return to the negotiating table nor laying down an ultimatum to the British government to find a solution in 30 days, as is being reported by some outlets.

What she is repeating, again, is that the backstop could become a dead letter overnight once the United Kingdom chooses and negotiates a post-Brexit future for itself.

While the mechanics of the backstop are complicated, the problem it solves is very simple: the only way you can have a border free of checks and physical infrastructure is if both sides of that border have the same customs and regulatory framework.

For much of the last half century, even when the land border between Ireland and Northern Ireland was heavily policed and militarised, the shared policy of both the Irish and British governments has been to have few regulatory barriers between the two nations. That’s part of why both countries joined the European Communities on the same day, part of why both countries remained outside the Schengen agreement, and why Northern Ireland has a different regulatory regime for agriculture than the rest of the United Kingdom.

Regulation and a shared open market alone can’t create a demilitarised border, but they are a prerequisite of it. But now that the United Kingdom is leaving the European Union, the UK has the option of leaving the regulatory and customs orbit of the European Union, and by extension that of Northern Ireland. That means a return to significant border checks. There is no border in the world outside of the regulatory umbrella of the European Union’s single market that is free of border checks.

The United Kingdom has two options. Firstly, for the whole of the United Kingdom to remain within the customs and regulatory orbit of the European Union, the downside of which being that the UK remains subject to vast swathes of regulation that it no longer sets and that it cannot meaningfully exercise the regulatory freedoms delivered via Brexit. Or, secondly, for Northern Ireland to enter its own customs and regulatory zone, allowing the rest of the United Kingdom to diverge.

The backstop in its current form provides an insurance policy that, in the lack of agreement between the United Kingdom and the European Union on a lasting trade agreement, the whole of the United Kingdom will stay within the customs and regulatory orbit of the EU. This is an astonishing diplomatic achievement that goes well beyond what the European Union wanted to give, as the bloc fears it allows the United Kingdom to access a huge share of the benefits of single market membership without a financial contribution and with freedom from many of its rules.

The only other negotiable alternative – and equally importantly the only alternative which doesn’t drive a coach and horses through 30 years of British political strategy in Northern Ireland – is to have a thicker customs and regulatory border in the Irish Sea.

A no-deal Brexit doesn’t resolve that issue because fundamentally, no deal is not an end state – the United Kingdom will still want a trade agreement with the EU and will still have to face the same choice about the Irish border. But once the British government decides which regulatory future it wants and wins a majority in parliament to support that future, the backstop ceases to exist. That is a process which, as Merkel said yesterday, could take 30 days. Or perhaps 300 years, given the current state of British politics.

The present government’s post-Brexit aims include the introduction of free ports (special customs and regulatory zones within a country) and a deep and meaningful trade agreement with the United States (which will require a thickening of the regulatory border between the United Kingdom and Northern Ireland in any case). So, bluntly speaking, there is a very simple off-the-shelf solution for the United Kingdom: a regulatory border in the Irish Sea and distant relationship with the European Union for the rest of the United Kingdom.

But this option cannot be delivered by this parliament, because a critical mass of Conservative backbenchers won’t vote for it, and the Democratic Unionist Party, without whom the Tories cannot remain in office, will bring down the government over it.

It comes back to the overarching problem that the Conservative Party has had since 23 June 2016 and which it shows no sign of being able to overcome: while there is in theory a coalition for Brexit in parliament and in the country, the party has yet to find a way to knit them together an enduring coalition for any form of Brexit in practice.