I have written before for this magazine about the unfortunate, and unwarranted, way that Irish nationalism seems to get a pass when it comes to its uglier side. Almost everywhere else, a movement (let alone an armed movement) harbouring territorial ambitions against its neighbours gets short shrift from the international community. Not so Greater Ireland.

This strange attitude existed before the Belfast Agreement. It helps to explain why that treaty ignored most of the norms about how disputed borders are normally handled, creating a guaranteed pathway to moving the Irish one that fatally undermined any hopes that Northern Ireland would move towards a more normal political culture.

The whitewashing of the IRA since 1998 has certainly not helped. Whatever Tony Blair’s original intentions, it has helped to legitimise and normalise Sinn Féin, perhaps the only major European party with a terrorist wing, and dim the memory of the bloody atrocities celebrated by many of its elected representatives (and perpetrated by some of them).

The horrifying events unfolding in Israel are a salient reminder of why this should not be allowed to happen.

Mary Lou McDonald may have just about managed to condemn Hamas’ brutal assault (chief target: an EDM music festival; 260 ravers bravely slaughtered), but her party’s heart clearly isn’t in it. One TD said on X that condemnations of the attack added up to “only Palestine has no right to defend itself”.

Meanwhile Ógra Sinn Féin, the party’s youth wing, has been tweeting endlessly about ending the so-called “apartheid state” in Israel (and blaming those dastardly Brits, naturally).

The apartheid language grimly echoes the republican framing of Northern Ireland

Ireland is not the only country whose leftists share an unhealthy fixation on the world’s only Jewish state. Jeremy Corbyn’s leadership of the Labour Party saw the antisemite left come crawling out of the woodwork in the United Kingdom, too.

It definitely hits a bit different, though, coming from a party that both views its own cause in very similar terms to Hamas (expelling planters from its ethnic soil) and has a long history of employing violence to try to achieve it. The spectre of terrorism is still conjured opportunistically against such horrors as a light-touch regulatory regime between the Province and the Republic.

Even the apartheid language grimly echoes the republican framing of Northern Ireland. Their worldview has no space for Ulster Unionists to be their own people with competing aspirations, so the refusal of the six counties to join an independent Irish state could never be legitimate.

All this would matter less if Sinn Féin were still a marginal force in the south. Its rise in Northern Ireland is not excusable — nationalist voters returned the avowedly constitutional SDLP throughout the Troubles — but it is at least understandable as a response to the trauma of those decades.

The Republic, on the other hand, is a relatively prosperous (even once tax-dodging American corporations are taken out of the figures) and mature European democracy. It has no excuse. Yet Sinn Féin is on the rise there, too. The cordon sanitaire maintained by the two major parties is close to breaking point, and few people now doubt that the republicans will form a government sooner rather than later.

From a unionist perspective, having them in power on both sides of the border isn’t necessarily the setback some people assume. As we have seen in the aftermath of the Brexit vote, the separatists’ best hopes of persuading swing voters to back Ireland in a border poll was persuading them that it’s the path back into a nice, normal, non-Brexit-y country. Sinn Féin hardly helps that impression.

Nor is it obvious what will happen when McDonald and her colleagues realise their ambitious plans to expand the Irish welfare state (to neutralise the pro-UK killer argument: the NHS) run into the reality of Ireland’s economic position (source: its GNI figures) and dependence on generous tax policies (source of those GDP figures).

It will nonetheless be a sad day for Ireland when it bestows the office once held by the likes of Garret FitzGerald on somebody from the violent republican tradition that he, and so many other Irish politicians, so sternly opposed. It will become surely the first European nation since the Second World War to return an armed insurgency to elected national office.