AS A small, cosmopolitan European capital, Dublin is a delight to visit. Georgian mansions recalling its role as the second city of the British Isles alternate with boutiques and cafés, buzzing with chatter in Spanish or Polish. And in the smart centre, the economic upturn is now palpable. On paper at least, the country has rebounded from recession and bail-out, posting GDP growth last year of 7.8%, five times the euro-zone average.

But there is something else in the spring air. Adorning many handsome facades there are sepia posters of men bearing rifles. Over Easter weekend, the bustle will cease as Ireland commemorates a founding moment: the weeklong uprising in 1916, during the first world war; it is recalled in British annals as a stab in the imperial back and in Irish ones as a heroic self-sacrifice.

The execution of its leaders, as much as the Easter Rising itself, triggered a maelstrom of events: a surge of anti-British rage and harsh counter-repression; a treaty in 1921 establishing two Irish parliaments (a northern one inside the United Kingdom, a southern one outside); and a civil war between supporters and opponents of that compromise.

Those wounds still fester. In other countries, historical ceremonies help transcend domestic squabbles. Not in Ireland, stuck in a deep political impasse, only explicable via the feuds of the past. Fine Gael, a centre-right party whose forebears backed the 1921 accord, has just lost control of the legislature after an election in which its vote slumped to 25.5%. Nor was there a triumph for its rival, Fianna Fail, a party of pragmatic centrists who descend from opponents of the 1921 deal. It improved its score but only to 24.3%. Neither can easily form a government and each mistrusts the other.

With the combined tally of the civil war-based parties now below 50%, is Ireland exorcising old demons and looking ahead? No such luck. The next biggest parliamentary bloc is Sinn Fein, with a 13.8% share; it claims to be the main moral heir of the 1916 insurgency (and will stage separate commemorations next month). Far more fiercely than Fianna Fail, Sinn Fein views all the political arrangements which followed the 1916 rising as a betrayal. Although it now shares power in Northern Ireland’s government, it also insists that its military wing, the Irish Republican Army, was justified in its 25-year war, ending in the mid-1990s, to end British rule in Ulster.

Since the Northern Irish deal of 1998, Sinn Fein has vowed to pursue a united, socialist Ireland peacefully. But some hardliners think the 1998 compromise, too, was shabby, and are fighting on. One such group killed a prison officer in Belfast this month.

Thus Ireland’s prime minister, Enda Kenny, may feel uncomfortable as he watches this weekend’s parades. His Fine Gael party represents the country’s most anglophile camp, and it abhors irredentists who call the rising unfinished business. Some in Fine Gael believe the rising was unnecessary; they think independence was won not by force but by Irish parliamentarians in London who operated peacefully and could have prevailed.

For all their intensity, Ireland’s internal arguments would be manageable, were it not for another spectre. That is Brexit, and the risk that Ireland might again have to choose between continental Europe and a non-European Britain. In Mr Kenny’s cautious words, this outcome could cause “serious difficulty” for Northern Ireland, whose peace deal is predicated on the United Kingdom and the Irish republic (and thus both bits of Ireland) being in the union and working together to get European benefits.

To see, at a deeper level, why Brexit is unwelcome, take another history lesson. In centuries past, England, Ireland and the continent made an ugly triangle. England saw Ireland as a soft underbelly which continental foes might exploit; Irish patriots looked to the continent for succour. In 1798, Irish rebels defied the Crown, aided by France; the insurgents of 1916 took help from Germany.

When Britain and Ireland both joined the then European Economic Community in 1973, a prettier shape emerged. As formally equal partners, the two Anglophone lands collaborated in Brussels. Ireland was keener on farm aid than Britain; but over trade and regulation, British and Irish eyes often met. Ireland gained continental links without sacrificing its ties to Britain. This happy alignment will end if Britain marches out, leaving Ireland lonely. Some wonder if it might feel pressured to leave the EU, too. Irish manufacturers fear paying duties on British-made inputs; and if Britain eased regulations on its own businesses, their Irish competitors, following European rules, would howl.

Brits not out

Horror of Brexit unites politicians in opposite corners. Ask two youngish members of the new legislature. Paschal Donohoe, the Fine Gael transport minister, says he has enjoyed working with Britain in Europe, for example to support liberal aviation regimes; but with or without Britain, Ireland will stay in the EU. Despite Britain’s absence, Ireland has benefited from the “competitive rigour” of the single currency, he believes. Eoin O’Broin, newly elected to parliament for Sinn Fein, loathes the idea of an EU external frontier running through Ireland. But whatever Britain does, he wants to be in the heart of European politics, fighting Mr Donohoe’s liberal ideas alongside leftist allies such as Syriza of Greece, or Jeremy Corbyn’s Labour Party in Britain.

For centuries, Irish people have found ingenious ways to divide their lives between the two islands, even when relations were frosty or worse, as they were in 1916. Britain and Ireland have long used different currencies: that has been a nuisance, not a catastrophe. The reappearance of a customs and security border between north and south would be more serious. Geography and kinship mean the two countries must muddle along. But even for Irish anglophiles, choosing Britain over Europe would be almost unthinkable. That is the newest lesson of Easter 1916.