Daniel Hannan is one of the most intelligent and sophisticated of the Brexiteers. The longtime Tory member of the European Parliament has a double first in modern history from Oxford, speaks fluent French and Spanish, has published several books and edits a journal of conservative ideas.

And yet he can pronounce on the failure of the Belfast Agreement without having much notion of what it is. Hannan’s column in the Daily Telegraph last Saturday was part of what seems to be a concerted assault on the agreement from leading pro-Brexit figures.

The former Northern Ireland secretary Owen Paterson tweeted the previous day: “The collapse of power-sharing in Northern Ireland shows the Good Friday agreement has outlived its use.”

On Monday, Labour MP Kate Hoey followed up by declaring the agreement “unsustainable”.

Hannan was the only one of the three to offer any substantial analysis. But for a trained historian and professional politician, that analysis was breathtakingly ignorant. “The original deal,” he wrote in the Telegraph, “represented a bribe to two sets of hardliners who, having opposed power-sharing, came to support it when they realised that they would be the direct beneficiaries. For 20 years, Sinn Féin and the DUP have propped each other up like two exhausted boxers in a clinch.”

In these mere 49 words, there are three enormous misconceptions. First, the deal whose 20th anniversary will be marked in April, is not primarily one between any parties in Northern Ireland, hardline or otherwise. It is, as its formal title makes rather clear, an “Agreement between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of Ireland.”

It is an international treaty registered with the United Nations.

Second, the internal aspects of the “original deal”, setting out the arrangements for the government of Northern Ireland, were not agreed by parties that opposed power-sharing.

The Ulster Unionist Party, which went on to take the office of first minister in the person of its leader David Trimble, had taken part in a power-sharing administration at Stormont as far back as 1974. The SDLP, under John Hume, was not only not opposed to power-sharing but had pioneered the idea.

The other parties to the “original deal” – Sinn Féin, Alliance, the Women’s Coalition and the small loyalist parties – supported the establishment of a power-sharing executive.

Since this was a key part of the deal they were signing up to, how could they not have done so? The only party that opposed power-sharing in 1998 was the Tories’ current ally, the Democratic Unionist Party, and it had no part in the making of the agreement.

Shocking

Third, Hannon the modern historian seems to think that “Sinn Féin and the DUP” have been in government together in Northern Ireland “for 20 years”. In fact, the two parties formed or dominated executives for just 10 years, between 2007 and 2017 (with interruptions).

All of this is shocking but not at all surprising. Some of the most prominent Brexiteers have always hated the Belfast Agreement. In The Price of Peace, his long pamphlet for the right-wing Centre for Policy Studies, published in 2000, Michael Gove characterised the entire peace process as nothing more than a capitulation to the IRA which, he insisted, would have given up if only British governments had taken a harder line. He even likened the peace process to appeasement of the Nazis in the 1930s.

But at least Gove wrote about it – the more common attitude in his circles is complete apathy. Northern Ireland was not mentioned in the Leave campaign and Boris Johnson’s refusal to talk about Brexit’s implications for Ireland continues right up to his most recent set-piece speech.

In this context, it is easy to understand how Hannon could imagine that his vague awareness of the Belfast Agreement counts as magisterial scholarly expertise and entitles him to make sweeping judgments about it.

Protection

The reality is that Brexit’s true believers have only just woken up to the fact that the 1998 treaty, which is effectively a part of the UK’s constitution, makes the hard Brexit they desire virtually impossible. The EU made it abundantly clear that the Irish question and in particular the protection of the agreement is central to any final deal.

The zealots ignored this truth for as long as they could. Forced to confront it, they have responded with a badly thought-out contention that the agreement is no great shakes anyway – with the implication that it doesn’t really matter if it falls apart.

If the Belfast Agreement must die so that the glorious ideal of Brexit may live, so be it.

This is cynical and reckless. It is also, as it happens, quite stupid: the Brexiteers believe that a liberated Britain will sign fantastic trade deals with countries all over the world. It seems not to occur to them that a country that casually tears up the most important international treaty it has signed since 1972 will not look like a very reliable partner to anyone.

Deleterious effect

But the attacks have another, more subtly deleterious effect. When something is being assaulted with such a mixture of ignorance and bad faith, there is a natural tendency to defend it absolutely. And the truth is that there really are serious problems with the Belfast Agreement.

In his column, Hannan complained that the 1998 deal has become almost a religious text, and in this at least he is right – to criticise it is a kind of blasphemy. This is unhealthy in itself, but it also ignores the obvious.

This in turn has given both Sinn Féin and the DUP a veto over the very existence of the assembly and the executive

The British-Irish part of the treaty is both good and robust. But the internal arrangements for the governance of Northern Ireland are patently not working. They have not led, as most people imagined in 1998, to the expansion of the middle ground – on the contrary, the rhetoric of “two traditions” has encouraged tribalism and squeezed out moderation.

This in turn has given both Sinn Féin and the DUP a veto, not just over policies, but over the very existence of the assembly and the executive. When they can’t or won’t work the systems, no one else gets the chance to do so either.

The assembly, meanwhile, can be paralysed by the “petition of concern” mechanism through which a majority vote can be nullified if it does not have the support of 60 per cent of members and at least 40 per cent each of unionists and nationalists. This was meant to be a way of protecting each side from gross abuses but it has been used 115 times in the last five years.

In 2015, for example, the DUP used it to overturn a majority vote to extend same-sex marriage to Northern Ireland. In 2016, Sinn Féin and the SDLP used it to block the extension of equality legislation to schools.

A system which has left the people of Northern Ireland with no official voice during a period when their vital interests are at stake in Brexit is obviously failing.

Just because it is under reckless attack, the Belfast Agreement should not be defended as holy writ. Its 20th anniversary would be a very good time to take stock of its strengths and weaknesses, successes and failures – if only the British government were not otherwise engaged.