From top: DUP leader Arlene Foster and aides in Stormont last night; Derek Mooney

Be in no doubt, the breakdown in talks yesterday is a crisis, a real crisis. This is bigger than last year’s collapse of the institutions. Much bigger.

Unlike recent ‘crises’ this is not merely about the two main Northern Irish parties playing hardball politics with each other and playing to their galleries, this is about a lot more.

While the legitimate demand for proper recognition of the Irish language may appear to be the catalyst for this crisis, the real cause is Brexit. And Brexit is the reason why this crisis, which is an existential crisis, will be extremely hard to resolve.

The architects of this crisis are not in Belfast, they are in London, specifically in Westminster. They are not just the 10 DUP MPs who have just reminded Arlene Foster and her crew that it is the MPs who now run the DUP show, they are also the slow learners in the Tory hardline Brexit fashion who have just now realised what Theresa May agreed to in Phase One of the Article 50 negotiations.

The hardline Brexiteers have just realised that the greatest threat to their Quixotic vision of a British Empire 2.0 exiting the EU institutions, Customs Union and Single market is the Irish/Irish Border.

Specifically, they have copped on to the fact that Brussels is determined not to flinch on either the letter or the spirit of the 1998 Good Friday Agreement and that staying in the Customs Union and having a Norwegian style EFTA arrangement is the only game in town.

It is as if the penny has just dropped with them that the Good Friday Agreement was not just a political document but a binding international agreement between two Sovereign Governments. An agreement whose contents and implications they had been gleefully ignorant of for years.

But now, as they come to realise that the Good Friday Agreement which they had ignored and dismissed is the one single thing that could most likely to scupper their hopes of a Britain entirely outside the EU, the Customs Union and the Single market.

So, they have concluded, they must find a way to sink or at least damage the Good Friday Agreement in order to undermine Brussels’ clear advantage in the negotiations. In this endeavour they have willing helpers, though they may see them as useful idiots, in the form of the 10 DUP MPs.

While Stormont was up and running and the British Government had a secure majority, the DUP MPs may as well have been MEPs – plenty of status, occasional forays on to the media, but absolutely no real power or influence.

But the collapse of the Executive and the suspension of the Assembly, courtesy of Sinn Féin, and the 2016 UK election result, courtesy of Theresa May and the Tories, catapulted the backwoods men of the DUP – and you can guess how deep in the back woods a DUP-er backwoodsman can be – not just into the spotlight, but into a spotlight that come complete with a driving seat with real leverage.

With those two events, the centre of gravity of the DUP party moved firmly and resolutely from Stormont to Westminster. Foster was now the King overseas, but at home. She can travel down south to give impressive speeches, she can meet gay rights groups and Irish language organisations, but the MPs were the ones with the power. Something we have seen come to fruition this week.

The DUP MPs are on the same wavelength as the hardline Tory Brexiteers and now have the ability to deliver to the Brexiteers, something they cannot get via the Tory cabinet or House of Commons, a possible way to punch a hole in the Brussels Article 50 negotiating position.

The Brexiteers want, as a good colleague of mine termed it in a WhatsApp message this week, to screw a brass plate on the coffin of the Good Friday Agreement. They want this, not because they hate the Good Friday agreement – most of them haven’t a notion what is actually in it – but because it is a means to an end, and that end is Brexit.

Not that the DUP MPs will cry any tears over the demise of the Good Friday Agreement, many of them built their early careers on opposing it, with one Sir Jeffrey Donaldson quitting the UUP to join the DUP over Trimble’s acceptance of it.

So now the fate of the Brexit negotiation, the future of the Good Friday Agreement and the return of devolution to Northern Ireland are inextricably linked.

You see now why I say this existential crisis will take a lot of work and a lot of time to resolve.

The one bright spot just now is that the place where you find the deepest understanding of the Good Friday Agreement – both in letter and spirit – is not Stormont Castle, Number 10 Downing Street or (regrettably) Government Buildings, Dublin, but the EU Commission and Council buildings in Brussels.

There are times when it seems that M. Barnier has a deeper understanding of what the Good Friday agreement is about than some of the members of our own Government (an issue I have touched on here before). It is as if members of this Government were disinclined to talk about the Good Friday Agreement for fear of acknowledging the key part played by Bertie Ahern and a succession of Fianna Fáil Ministers in bringing about political progress in the North from David Andrews to Brian Cowen to Dermot Ahern to Micheál Martin.

That will have to change. Both the Taoiseach and the Tánaiste will have to rise considerably above the petulance we saw in the Dáil today from Simon Coveney and recognise that this is a major crisis and one to which this Government and the last Fine Gael-Labour one actively contributed by taking its eye off the ball.

It will also have to change its modus operandi and seriously upgrade and improve its political antennae within Northern Ireland. It will have to take to all parties regularly and meaningfully, not just two. It will need to learn how to understand the DUP (another issue I have discussed here before).

How did it miss the power shift from Stormont to Westminster – how did it allow itself to be both convinced of – and then become a persuader for – the idea that a deal on devolution was imminent?

It also needs to recognise that it does not have what Albert Reynolds, John Bruton and Bertie Ahern had in their day: a capable and committed partner in the British Government.

May’s government is not merely dependent on the DUP, it is dependent day-to-day on the most antediluvian faction of the DUP – its MPs. That compromises May’s government in its political dealings with the Irish Government and Irish Ministers and SpAds need urgently to wake up to this fact – I think the Irish officials have long since copped on to this, but it seems they are not always listened to.

It does not make the British Prime Minister or NI Secretary of State untrustworthy, it makes them something much worse, it makes them weak. Negotiating with a weakened partner across the table is a problem as you can never know that they can sell what they agree with you back to their people.

The first step in bolstering the chances of a real partner in this process is, as both Micheál Martin and the SDLP’s Colum Eastwood have proposed, must be the formation of the British Irish Intergovernmental Conference.

It is the key element of the Good Friday Agreement – and the protection of the Good Friday agreement and the principles on which it is based – must be the priority for both devolution and Brexit.

Derek Mooney is a communications and public affairs consultant. He previously served as a Ministerial Adviser to the Fianna Fáil-led government 2004 – 2010.  Follow Derek on Twitter: @dsmooney

Eamonn Farrell/Rollingnews