Never mind the EU’s attempt to shift the blame for its own Covid vaccine failures to others – the sum of Charles Michel’s contemptible charge that the UK and the US have introduced “an outright ban on the export of vaccines”.

For while the Union’s ponderous approach to roll-out will cost its members jobs, wealth and lives, and may turn out to be politically significant in the longer-term, it is not institutionally significant – in the sense that it is driven by a treaty, democratic institutions and law.

The same holds for other disagreements in the wake of the Brexit trade deal – over live shellfish, say, or financial regulation.  These are ultimately political problems which can be solved by finding political solutions.

However, matters are less straightforward when it comes to the driver of the present tensions, which is set to be in place even after every EU citizen who needs a vaccine has got one: the Northern Ireland Protocol.

For the Protocol, as part of the Withdrawal Agreement, is part of an international treaty, has been given domestic effect by an Act of Parliament, and is subject under the terms of the Agreement to judgements by the European Court.

And, to put the problem in a nutshell, the Protocol is incompatible with the Belfast Agreement to which it is formally committed – arguably legally; certainly politically.

Legalities first.  Part 1 (iii) of the section of the Agreement on constitutional issues says that “it would be wrong to make any change in the status of Northern Ireland save with the consent of a majority of its people”.

If putting it under a different customs code, VAT laws and regulatory arrangements to Great Britain isn’t a change to the province’s status, what is?

This is why David Trimble, the co-architect of the Agreement, for which work he co-won a Nobel Peace Prize, has said that the Protocol “drives a coach and horses through the Agreement”.

Next, politics – which takes us to David Frost who, as he puts it, has “taken temporary operational steps to minimise disruption in Northern Ireland”.

The recently-appointed Cabinet Minister was able to pray in aid “the improper invocation of Article 16” by the EU over vaccines which “has significantly undermined cross-community confidence in the Protocol”.

This was a reference to the recent letter to Boris Johnson from the Combined Loyalist Military Command claiming that the Protocol undermines the basis on which loyalist groups “agreed their 1994 ceasefire and subsequent support for the Belfast Agreement”.

And while the Agreement is a legal document it is first and foremost a political one: in broad terms, it sets out a settlement which commands enough consent from unionists and nationalists alike in Northern Ireland to keep the peace there.

If one or other of those communities takes exception to the Protocol, and withdraws support from the Agreement, then the latter can’t do its work.

We are not there yet, and may never be.  But there is a danger of support or otherwise for the Protocol dividing on political lines in Northern Ireland during the run-up to the next Assembly elections: the potential consequences need no spelling out.

Finally, the indispensability of the Belfast Agreement is written into the Withdrawal Agreement, which declares as follows in its Article 1 (3) on objectives.

“This Protocol sets out arrangements necessary to address the unique circumstances on the island of Ireland, to maintain the necessary conditions for continued North-South cooperation, to avoid a hard border and to protect the 1998 Agreement in all its dimensions.”

Why haven’t Unionist politicians made more of the incompatibilities between the Belfast Agreement and the Protocol?  The answer is that the main nationalist party in Northern Ireland has always supported the former, but the main unionist one has not.

Lee Reynolds’ magisterial article on this site in 2018 set out the Democratic Unionist Party’s history with and attitude to the Agreement, which it originally opposed.

It is scarcely surprising, then, that the Unionist champions of the Agreement tend to cluster around Lord Trimble himself, including two of his former advisers who have written for this site: Paul Bew and Roderick Crawford.

This imbalance has had consequences in America, in which the nationalist perspective on the Agreement has been vigorously put; the unionist one, less so.

As for government UK-wide, “the British Embassy needs to be at the top of its game and be fully equipped with the right arguments,” Jonathan Caine wrote on ConservativeHome recently. “This is not something that has always been the case.”

So much for the problem – that the Agreement and the Protocol are at odds.  What of the solution?  The Government can’t, won’t and shouldn’t resile simply from the Protocol.

Even were Ministers minded to make us an international pariah, the Commons wouldn’t allow them to do so, anyway.  So could the Government aim to shift the checks that are causing such a flurry from East-West to North-South?

Not while the Protocol holds – and, in any effect, our own logic suggests that, since such change would be as unacceptable to nationalist opinion in Northern Ireland as the Protocol presently is to unionist opinion, it would imperil the Agreement too.

So what’s the answer?  The best we can offer is that much depends on whether the EU is as committed to the Agreement as it claims to be – which its own recent actions over the vaccine have thrown into radical question.

If so, it would co-operate in the extension of grace periods for food, parcels and medicines, and agree that supermarkets in Northern Ireland can adapt their product monitoring systems to replace export health certificates.

The Union would also go very light on pushing for permanent border posts, and on dymanic alignment with its sanitary and phytosanitary rulebook.

However, the EU presumably takes the view that it is unwilling to allow the borders that protect its internal market to be compromised in such a way.

And even if the Commission and member states came round to a different view, there is no knowing what the ECJ will do with cases taken before it.  None of which renders the Protocol any more practicable – and reconcilable with the Belfast Agreement.

As Henry Hill suggested recently on this site, Lord Frost’s recent actions suggest that such is his take too; that the Government must proceed on the basis that the Protocol is unworkable and, over time, persuade the EU that this is so.

It may be that the Government finds itself building alliances with two apparently unlikely partners: the Irish Government and the American Government.

For while protecting the internal market is important to the former, it will be less so than protecting the Belfast Agreement, and ensuring that the Great Britain to Northern Ireland checks work as smoothly as possible.

If they don’t, after all, and the eventual consequence is disruption in Northern Ireland, then a threat returns to the Irish government which it triumphantly averted during the Withdrawal Agreement negotiation: a harder border on the island of Ireland itself.

What would work for the Irish Government would also work for Joe Biden.  He and his team have a green perspective, to be sure, but they understand the Belfast Agreement, and that it rests on unionist as well as nationalist consent.

A light touch revised Protocol may be as unacceptable to the EU in the long term as the short.  If that is so, then so be it.  But if so, could it please spare us the claims of how it is set on protecting “the 1998 Agreement in all its dimensions”?