The Good Friday Agreement and Brexit

12th April 2021

Before the Brexit referendum, one British politician made an emphatic statement about the impact of Brexit on the position of Northern Ireland:

‘Relations between London and Dublin are by far the warmest they have ever been since Irish independence, and the people of Northern Ireland are among the beneficiaries of that.

‘For that, the credit goes to a whole succession of British and Irish leaders, and to the tireless diplomacy of the United States. Yet it has also partly been facilitated by both countries being part of a common framework.

‘If the UK were not in the EU, the impact on such close relations, though hard to quantify, would certainly not be positive.

‘The Good Friday Agreement was based on the assumption that the two countries would be in the EU together, and the various cross-border institutions it established are built on that.

‘Hundreds of millions of euros of European funds are currently diverted into the border region through a special peace programme.

‘Most important of all, the open border between Northern Ireland and the Republic would be called into question.’


The key sentence of that passage bears repeating:

‘The Good Friday Agreement was based on the assumption that the two countries would be in the EU together, and the various cross-border institutions it established are built on that.’


Who was this politician?

Was it some starry-eyed Europhile writing in some left-wing magazine?

No, it was former Conservative foreign secretary William Hague writing in the Daily Telegraph on 9th May 2016.


Hague’s warning was not the only one – and he was also not the only one to make the connection between the European Union and the Good Friday Agreement.

The then Taoiseach Enda Kenny said, just days before the referendum:

‘When the Good Friday agreement was concluded 18 years ago, the detail of the negotiations and the agreement itself were brought about as a result of intensive engagement by the British and Irish governments in conjunction with the Northern Irish political parties.

‘But often underestimated was the international support for the process, not least that of the European Union.’


And if one looks at the Good Friday Agreement itself, you will see the following recital:

‘The British and Irish governments […]

‘Wishing to develop still further the unique relationship between their peoples and the close co-operation between their countries as friendly neighbours and as partners in the European Union’

The agreement also expressly provided that the north-south ministerial council ‘consider the European Union dimension of relevant matters, including the implementation of EU policies and programmes and proposals under consideration in the EU framework. Arrangements to be made to ensure that the views of the Council are taken into account and represented appropriately at relevant EU meetings’.

Indeed, there are eight mentions of the European Union in the agreement.


Of course, an agreement made in 1998 did not and could not have anticipated the United Kingdom voting to leave the European Union in 2016 and then leaving in 2020.

But that shared membership of the European Union was a presupposition cannot be sensibly denied.

As Hague also points out about Gibraltar, shared membership of the European Union was a handy and effective solution to tricky cross-border issues.

The European Union was a useful geo-political work-around for many otherwise insoluble problems. 

And so be departing from the European Union, such advantages of membership were removed.

This should not have been a shock.

Hague set this out plainly in the Brexit-supporting Telegraph, and the Taoiseach also put his name to articles explicitly stating this.


Brexit, of course, is not in and by itself a contradiction of the Good Friday Agreement – in that the Good Friday Agreement still is in force now that the United Kingdom has departed the European Union.

In the first Miller case, the supreme court was asked to rule against the Article 50 notification, and they stated in respect of the legislation implementing that agreement:

‘In our view, this important provision, which arose out of the Belfast [Good Friday] Agreement, gave the people of Northern Ireland the right to determine whether to remain part of the United Kingdom or to become part of a united Ireland.

‘It neither regulated any other change in the constitutional status of Northern Ireland nor required the consent of a majority of the people of Northern Ireland to the withdrawal of the United Kingdom from the European Union.’

As such continued shared membership of the European Union may well have been a presupposition of the Good Friday – but it was not (as a lawyer may say) a condition precedent.


The Good Friday Agreement is, in terms of its practical importance, perhaps the most significant single constitutional instrument in the politics of the United Kingdom.

It is of far more practical importance than, say, Magna Carta.

It shapes what is – and is not – both politically permissible and politically possible.

It largely explains the curiously elaborate – and, for some, counter-intuitive – nature of Brexit in respect of Northern Ireland.

It meant that the clean absolute break with the European Union sought by many Brexit supporters did not happen.

The Irish border was to be kept open.


But the Good Friday Agreement does not only protect the nationalist community, it also should protect the unionist community.

And the Brexit arrangements – with a trade barrier effectively down the Irish Sea – is seen as much as an affront to the unionists as a visible land border infrastructure would have been an affront to the nationalists.  

There is no easy answer to this problem – perhaps there is no answer, easy or hard.


It took membership of the European Union to make the Belfast Agreement possible.

Perhaps there is no alternative geo-political workaround to take its place.

Had the United Kingdom stayed within the single market and the customs union, even if as a matter of legal form it would not technically be a member of the European Union, then perhaps this problem could have been averted.

But the fateful decision by then prime minister Theresa May in the months after the Brexit Referendum that Brexit would mean leaving the single market and the customs union meant that problems in respect of the position of Northern Ireland would become stark.

And as nods to the articles by Hague and Kenny show, it cannot be averred that the United Kingdom government was not warned.


Thank you for reading this post on this daily law and policy blog.

If you value this free-to-read post, and the independent legal and policy commentary this blog and my Twitter feed provides for both you and others – please do support through the Paypal box above, or become a Patreon subscriber.


You can also subscribe for each post to be sent by email at the subscription box above (on an internet browser) or on a pulldown list (on mobile).


Comments Policy

This blog enjoys a high standard of comments, many of which are better and more interesting than the posts.

Comments are welcome, but they are pre-moderated.

Comments will not be published if irksome.

35 thoughts on “The Good Friday Agreement and Brexit”

  1. You are entirely right that the UK government was warned about the complexity of the Irish border. It was warned before the referendum, after the referendum, during the negotiations, after the negotiations. The stupidity of May setting up a red line without thinking through the consequences was a key point in the long stupid process.

    A key factor throughout has been the ability of Brexiters to disregard these warnings. It is only “little” Ireland after all. So we had Priti Patel talking about starving Ireland into submission, David Davis saying it was an issue over an “internal” border, Johnson saying going from Northern Ireland to the Republic of Ireland is like crossing from Kensington to Hammersmith, Rees-Mogg talking up Ireland choosing to leave the EU to protect its relationship with the UK, etc.

    They really don’t get that Ireland is a separate country. Even if they understand the fact that Ireland has its own government, they just can’t see that it has its own interests. They don’t get how powerful Ireland is because the EU is a single negotiating block and will always protect a member. It is a mental blindspot among senior Brexiters.

    Still, any folly on the part of the UK government pales when compared with that of the DUP. What on earth did they think was going to happen?

    1. In answer to your question, I genuinely don’t believe the DUP or at least its leadership, are capable of rational thought in these situations. They also fatally undermined Theresa May’s attempt at a potential WA which would have obviated any border.

      Only this morning on BBC Today they were attempting to wind the clock back to 20 years ago when the GFA was signed (which they never endorsed).

      It’s so-called leadership like this that has helped sustain the loyalist unrest we see on the streets today; and BTW, with their shrill calls for a unity poll & their stupid violation of Covid restrictions, Sinn Féin are equally at fault.

      1. I don’t think there’s any doubt that the DUP wanted to undo the Good Friday Agreement (that as you say they never endorsed) and go back to the very hard border of fifty years ago before the UK and Ireland joined the then EEC together. They just couldn’t say so publicly lest people in Britain be alerted and change course. Of course they completely misread what Ireland could do to salvage something out of the situation.

        And indeed they continue to misunderstand. The NI Protocol is in fact a huge concession by Ireland, that the DUP are now trying not to take advantage of! Giving Northern Ireland the privilege of simultaneously being in the UK and the Single Market has the potential to “bake in” NI’s Britishness in the long term, as it would lose that privilege in the event of a united Ireland.

        I understand there has been quite a lot of interest shown by British firms wanting to move operations to NI. They won’t be so keen to invest if the DUP continue to stir trouble and prevent the Protocol from operating.

        1. The border between NI and Ireland was never “very hard”. There was (and still is) free movement of British and Irish people across it; passports have never been required. Passports were never necessary for travel between Dublin and Liverpool. (There were restrictions during WW2/The Emergency.)

          From April 1923 there was a Customs Border, with border posts on “approved” roads. For the ordinary private traveller these were mostly an inconvenience, no more than that. Quite often you weren’t even stopped, simply waved through. Smuggling was common and accepted, particularly during WW2 when butter, for example, was in short supply in NI. There was a steady trade smuggling prohibited items such as condoms to the south.

          Rather different for businesses, though; then it was “hard”, and there was none of the cross-border in milk and dairy products activity etc that there now is.

          1. Passport controls and movement of goods have always been quite different from one another between Ireland and the UK. I was very much focused on the movement of goods aspect. There has never been and is unlikely to be significant passport control due to the Common Travel Area’s inviolable status.

            Where goods are concerned, being a quiet backwater back in the day and there being no WTO, Ireland and the UK certainly had some discretion over its “hardness”. Nevertheless it was a full international border and were it to be implemented today it would definitely have to be “hard” not least because if it wasn’t it would attract smugglers from around the world to exploit it.

    2. “They really don’t get that Ireland is a separate country. Even if they understand the fact that Ireland has its own government, they just can’t see that it has its own interests. They don’t get how powerful Ireland is because the EU is a single negotiating block and will always protect a member. It is a mental blindspot among senior Brexiters.”

      Yes, and Brexiters get away with this because so many British people “don’t get” it either. Hence such common usages as “British Isles” (which haven’t been wholly British for a century now) and “Southern Ireland” (lest that word ‘Republic’ stick in the British craw). And the observations by Irish people (hear, for example, Naomi O’Leary on a recent Breaking Britain podcast) that some British people are surprised to discover that the Queen is not the Irish head of state and that Ireland no longer does business in pounds sterling.

      We have a lot more ‘working on the past’ to do (and not only with regard to Ireland).

  2. Clearly true. And it was emphasised by the EU in its selection of 3 key issues for inclusion in the Withdrawal Agreement. Money (haggling) Rights of Citizens (not going too badly I think) and the Irish Border. The third was almost the most difficult and deeply misunderstood by all Brexit fans doing the negotiations, throughout and to the extent that the WA was agreed on the basis of willful misunderstanding and misrepresentation. So now we have, in contrast to the situation of the late 1960s and early 1970s, a situation where the Unionist component of the population perceives that they are oppressed by the UK government and possibly the Irish(/EU) one as well. This needs really intelligent and immediate negotiation or it will get further out of hand,

    1. Not much chance of intelligent and immediate negotiation I’m afraid, when we have a prime minister who appears to be keeping his head down in the hope that the problem will magically go away.

  3. Thank you for this excellent analysis and the reminder that the denial by many Brexiteers of the centrality of the EU to the GFA is pure and simple deceit.

  4. **Pedant Alert**

    “As such continued shared membership of the European Union may well have been a presupposition of the Good Friday – but it was not (as a lawyer may say) a condition precedent.”

    I think this should refer to a condition subsequent, ie a condition of the continued applicability of the GFA.

    1. Thank you – but I am happy with it being a condition precedent – though I see your point about it being a condition subsequent.

  5. Thank you for the clearest and most concise article I have read on this issue.

    Perhaps you could follow up with an article on Gibraltar and the Falklands and, indeed, the Brexit consequences for other British Protectorates. St. Kitts and Nevis, for example, trades almost exclusively with Guadaloupe which as an overseas department is actually a region of France. So another border with the EU…

  6. There is an answer: the UK rejoins the Single Market and Customs Union.

    That it may be unpalatable for the UK government does not stop it being an answer to the issues thrown up and does not stop the persistence of those issues being a choice on the part of the UK government.

    1. Simple answer to a complex question: the UK rejoining the Single Market and the Customs Union requires the EU agreeing.

      1. And right now, the bucket of goodwill towards the UK among the people and politicians of the EU is rather empty …..

  7. “As Hague also points out about Gibraltar, shared membership of the European Union was a handy and effective solution to tricky cross-border issues.”

    Indeed. One wonders what may now become of the tricky cross-border issue of Gibraltar now that the UK is no longer part of the same club as Spain.

    1. The answer to Gibraltar is that it has joined the Schengen group of nations. There is no physical border for people any more. So Brexit has reduced the “sovereignty” of the UK, by making it difficult for the UK to choose who enters its territory.

      As it is Gibraltar, this may not be a major issue in practice, but it ought to disturb the sovereignty fetishists. After all, an inability to distinguish between sovereignty and reality has been a key things that has got us where we are.

      In terms of goods, I think it would be impractical for Gibraltar to be used as a way of getting round the UK not being in the Single Market. It is a very short, very exposed and very highly watched border, unlike the one in Ireland. I am sure there is smuggling, but there always has been there, both because of the proximity of Spain and its closeness to Africa.

    2. It is worth remembering that the UK, as a prior member of the then EC, demanded that Spain bend the knee and give Gibraltar quite a sweet arrangement as a condition of Spanish accession. I doubt very much that Spain has forgotten that.

  8. Having just listened to David Runciman’s excellent History of Ideas podcast on John Rawls, it seems that once again the sensible solution that Rawls would probably promote, ie the status quo, will be shown to be impossible in politics. There was a solution that worked reasonably well, or at least well enough, we were warned about changing it, but the warnings were not heeded even by some who should have known better because they were blinded by ambition or poorly advised. So with luck there will be a short term solution cobbled together and ultimately the demographics will make a united Ireland possible. But retaining the half in half out situation is not a solution.

  9. Once Theresa May had needlessly boxed herself in with her red lines, it was inevitable that NI would become Brexit’s Achilles’ heel. It is not news that English politicians are ignorant of Irish and Anglo-Irish history and London even appointed a Secretary of NI who did not know that Unionists tend to be Protestant and Roman Catholics tend to be nationalists, nor than Partition deliberately created a pro Unionist / Protestant apartheid statelet, or that the British Army initially were sent to NI to protect the largely Catholic minority protesting for their civil rights… This ignorance is coupled with London’s centuries long, but continuing arrogance in its treatment of what was a former colony but is now a sovereign state. London seems equally negligent of the consequences of its politically expedient support and as thoughtless dropping of “no surrender” DUP. The government is one hundred per cent responsible for the recent violence and the possible unravelling of the GFA. A deliberately combative and provocative approach to the EU over the NI Protocol and the fact that the asinine DUP Brexit-supporting policy cuts off the DUP’s nose to spite it face, does not help. But then DUP actively opposed the GFA and voted against it. So it also should not be a surprise that Johnson’s administration seems unaware that the EU and USA are also important signatories and guarantors of the GFA and are unlikely to stand idly by as London witlessly allows it to unravel. All this was warned about but no heed was paid. But then British history and its relations with its colonies, Europe and the world are not taught in schools and whatever is taught is a jingoistic parody as accurate as “1066 and all that”.

  10. It feels like time to re-read Barbara Tuchman’s “The March of Folly”, her history of “the pursuit of policy contrary to the self-interest of the constituency or state involved”. A governance folly in her terms has to fit these criteria:

    (1) it must have been perceived as counter-productive in its own time, not merely by hindsight
    (2) a feasible alternative course of action must have been available
    (3) the policy must have been that of a group and persisted beyond one political lifetime (to make it a collective folly and not just the belly-flop of a single powerful fool)

    The three cases she treats are the Renaissance popes provoking the Protestant secession, the British loss of the American colonies, and the American conduct of the Vietnam War. It feels more likely by the day that the current form of BrExit will fit this sorry pattern.

  11. During the years that the Brexit arguments dragged on, I wondered why the Good Friday agreement would specify that there must be a more relaxed ‘intra-Europe’ type border rather than a normal international border. Therefore I tried to find the original source – the legislation, treaty, agreement or whatever – so I could read the exact requirements set out there. However I failed. I’m not sure if I was looking at the wrong documents, or just searching them ineffectively.

    Can anyone help me out by pointing me to the source (e.g. document url and clause/section number) so I can understand precisely what is at the bottom of this problem that seems, like so many others, to now rest in the hands of Johnson’s fantasy level of care.

    1. The simple answer is that there never was a “normal international border” between N Ireland and the Republic. Such a “normal” border would have meant a considerable hardening of what was present.

      The origins are historical. The original Home Rule Bills saw a “devo max” arrangement for all of Ireland, with parliament in Dublin. Unionists in the north resisted this. The Government of Ireland 1920 Act foresaw two Home Rule parliaments, one for northern Ireland and one for southern Ireland, with the island partitioned. The former came into existence; the latter didn’t, rather after the Anglo-Irish Treaty “southern Ireland” became the Irish Free State, a Dominion of the Crown. Northern Ireland remained part of the UK.

      A Common Travel Area was agreed early on; no passports were required for travel between the two parts of Ireland, or between the Free State and Great Britain. This is still the case. (There were some restrictions during WW2.)

      The Free State introduced tariffs on imports in 1923, and from April that year there were customs posts at the border, on “approved” roads, and on rail crossings. Cars entering the Free State required a certificate of temporary importation or triptyque. This was originally accompanied by a booklet which was stamped on entry and exit; there were major penalties if you were caught having crossed using an “unapproved road”. (There were exemptions for doctors, nurses, and vets.) Otherwise, for private travel, customs was barely a formality; you were often waved through without inspection; you were expected to declare any goods, but there were no full-on searches.

      The EU’s Customs Union made such customs posts at the border redundant.

      However, the “Troubles” resulted in major security infrastructure at major crossings; it was unnerving to have a squaddie with an SLR demanding to know why you were crossing the border. You could compare this sort of infrastructure to the Berlin Wall.

      The GFA made this too redundant, and the infrastructure was soon demolished. Other than road markings and signs, if present, the only way to tell that you are crossing an international border is a change in the tarmac.

      So, the documents you are looking for don’t exist; there never was a “normal” border, nor any desire (up to now) to have one. It just “was so”.

      1. Add in the fact that there are no passport control between the Republic of Ireland and Great Britain. Annoying people like me flying from here to Dublin always insisted on not showing my passport as ID to get on the flight – petty I know.

        And Irish citizens resident in the UK are entitled to vote in UK elections. I believe this was a concession to placate the formerly large number of people in Ireland, particularly round Dublin, who felt aggrieved that they lost their Britishness in 1921.

        So a regular international border has never existed on the island of Ireland, or between the Irish Republic and Great Britain.

        On the other hand, there has to be a border between the UK and the EU, because the UK decided not to be in the Customs Union. Whereas in the olden days, the Irish border only mattered in Ireland, now it matters to the whole of Europe.

        The UK was warned about the problem this creates…….and here we now are.

  12. The obvious question is, what were they thinking? But none of the answers seem palatable:
    “It doesn’t matter.”
    “We don’t care.”
    “It’ll sort itself out.”
    “We’ll blame the EU.”
    “Let them have a united Ireland.”
    “Let’s just get through this crisis, we’ll burn that bridge when we get to it.”
    “We’ll release some other news that day.”
    “We’ll blame Labour.”
    “We’ll bluster our way through it. It’s worked every other time.”
    “We’ll come up with some other narrative when that time rolls around.”
    “Can we send in the army?”
    “We’ll blame Tony Blair.”
    All of the above.
    None of the above.

  13. Whether the border is or was hard or soft is irrelevant. The future, if there is increasing violence, a change of the unionist/nationalist majority and the increase of smuggling will lead to the need for significant changes. If none of these come to pass then all will be ‘well’. But government has shown itself to be quite unable to address these issues in good time. All the running has come from the EU.

    1. It is reassuring that so many establishment figures quoted are so disapproving of Johnson. I particularly like Alan Duncan’s “an international stain on our reputation, a selfish, ill-disciplined, shambolic, shameless clot.” Don’t hold back, Alan.

      However it points up how spinelessly career-focused are the MPs who could do something about removing him. Shades of the GOP in America.

      1. And as with the GOP, the shame falls upon the electorate. That the UK has a Johnson or the USA a Trump is inevitable: among the teeming millions will be the blots of many a dishonourable individuals. But that so many adults are prepared to sacrifice what principles they might claim to hold dear (honesty, justice, etc, things we liked to think came almost automatically through breast milk and basic schooling) to support those that spout such self-serving hypocritical bare-faced nonsense, there’s the stain.

  14. Underlying the post and the comments is the notion that leaving the EU is somehow not a legitimate thing to do. That all these problems could be solved if Brexiteers just accepted that staying in the EU was a better choice.

    But that is not what democracy is about. Humans disagree. They have opinions. Democracy has evolved to cope with disagreements. International relations should aim to have good relations between states who have disagreements and differences. A process such as Brexit is something that politics is meant to address.

    The notion that the GFA had somehow tricked the UK into having to remain in the EU no matter what is clearly not tenable. The removal from a people of a fundamental right to choose how they are governed by some sleight of hand, without their consent that that was what was entailed in the agreement, is clearly undemocratic and unsupportable.

    The GFA creates institutions and processes that enable compromises to be made. It makes only one hard and fast statement and that is that NI is in the UK, which one would have thought meant the UK government made the rules and regulations and oversaw legal processes in NI. Nowhere does it say there must be an open border. So the current agreement ditches a clause that is in the agreement to preserve a clause that isn’t in the agreement.

    The problem has arisen because European federalists chose to use the peace agreement as a weapon to weaken the UK. This is a mistake, as we are now seeing.

    As a Brexiteers, I trust the RoI politicians to be sensitive enough to work this out, but I don’t trust the EU institutions or politicians. That’s why I voted to leave.

    Nothing has happened since 2016 to make me think voting to Leave was the wrong thing to do. Every occurrence has only confirmed my view that remaining in the EU would have been in the long term detrimental to the UK. My view that Brexit is positive for the UK has only hardened.

    1. Incorrect – that is not the assumption underlying the post. I know that because I wrote it.

    2. A Brexit that involved leaving the Single Market (which one notes is not a Brexit on which the British people expressed a democratic opinion) necessarily involved disruption of the arrangements that had been made with Ireland as part of the GFA and in the period since.

      Following that decision to leave the Single Market, the NI Protocol is the necessary mitigation agreed between the UK and Ireland, with the EU acting as Ireland’s agent in negotiations.

      Do not for one moment believe that the NI Protocol is somehow imposed on Ireland by the EU. If anything the reverse is true.

      1. Dan Hannan summed this up pretty well in the Telegraph. We should keep the NI protocol but look to make it work. The NI protocol exists because the EU offered nothing but annexation of NI.

        It wasn’t inevitable that the UK would leave the single market, and personally I was ambivalent. What I am not ambivalent about is the UK being meat on the EU’s plate. There is a clear divide between on the one hand nations of the EU who largely have accepted Brexit and want peaceful mutually beneficial relations with the UK, and on the other hand EU institutions that are behaving in aggressive ways towards the UK. They are waging war against the UK and not is essential the UK does not lose or we will be a ruled people. European nations and particularly Ireland need to be careful about what is being done in their name.

        1. It is not annexation, nor is it even close to annexation.

          However it is interesting that you use a word which in the British psyche is associated with Hitler’s Germany. Brexiteers such as yourself should beware polishing up a false narrative to justify anger.

          Certainly Britain finds itself in a difficult situation, but any anger should be directed at HMG.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.