Donald Trump’s announcement that he would lift tariffs on Irish whiskey imports to the United States capped off a visit that turned out to be more successful than Irish politicians and officials had dared hope.

Every encounter with the US president is a bare-knuckle ride, with several politicians and officials acknowledging in the days before the visit that anything could happen.

In advance of any meeting with Trump, emerging without an obvious disaster is the summit of their ambition. But his visit to Ireland went better than anyone expected.

The whiskey wheeze, announced on the 18th green at Doonbeg as he prepared to present the Irish Open trophy to Offaly’s Shane Lowry, was something the Irish side had sought to put on the table in recent months.

But there was no expectation that it would be concluded in such spectacular fashion – evidence once again that Trump is, first of all, a showman.

Three high-ranking sources who discussed the issue privately pointed to the role of Geraldine Byrne Nason, Ireland’s ambassador to Washington, who was ubiquitous over the weekend and who has, one person familiar with the landscape says, “cracked Trumpworld”.

“She is the Trump whisperer,” another said.

People around Government were keen to play down the significance of Trump’s comments on a united Ireland, even if they made headlines all over the world and infuriated Unionists and Conservatives in Northern Ireland and the rest of the United Kingdom.

Trump seems to have put some degree of forethought into his comments. Irish Government sources were aware the issue would be raised, though they did not know in what manner exactly.

Taoiseach downplays ‘overreaction’ to Trump’s call for united Ireland

What his calculation was in doing it is harder to fathom. Was it a friendly signal to Irish-American voters in advance of November’s midterm elections in the US? Part of his regular campaign of barbs against the UK? An attempt to curry favour with his hosts? Was it a combination of all of that plus Trump’s tendency to shoot from the hip on all sorts of issues?

Perhaps this is some evidence of Trump’s mad genius: he even managed to win over Sinn Féin. His comments brought Northern First Minister Michelle O’Neill and the leaders of the Scottish National Party and Plaid Cymru in Wales together on Monday. They said in a joint agreement, aimed at putting pressure on Downing Street to hold referendums on independence, that “Westminster’s time is coming to an end”.

Labour’s Ivana Bacik, more accustomed to denouncing Trump, issued a slightly pained statement in agreement with the president: “As Connolly-ite republicans, we recognise that Trump’s intervention on the unity question does mark a renewed and welcome focus upon the need for the Irish Government to take preparatory steps towards the holding of a unity referendum.”

Though the best line of the weekend was undoubtedly from Claire Hanna, the leader of the Social Democratic and Labour Party. “Turns out he’s not as orange as he looks,” she told her party conference.

Speaking on RTÉ Radio on Monday – in what looked like an attempt to do a lap of honour but also manage the fallout from Trump’s comments – the Taoiseach emphasised that co-operation between Dublin and London was the essential foundation of all progress in Northern Ireland.

There are fears that Trump’s comments might make it harder to make progress with the British on two issues that Micheál Martin identified in recent days in advance of a meeting with British prime minister that was due to take place this week. However, news of the death of Andy Burnham’s father emerged on Monday.

These are “legacy” issues, principally investigating Troubles-era crimes by the British security forces, and making clearer the criteria that a British government might use to decide about holding a Border poll in future. The Belfast Agreement is vague on the question.

Martin has mused about teasing it out with the British. In the wake of Trump’s comments – and the declaration by nationalist parties in Northern Ireland, Scotland and Wales on Monday that they intend to break up the UK – the UK government may be less inclined to explore the issue immediately.

Whatever comes out of the first Martin-Burnham summit, the two men can agree that the reality of statecraft and international politics in 2026 requires a facility in dealing with the unpredictable and mercurial occupant of the White House. This weekend demonstrated the necessity of that, but also, bluntly, the benefits of being Trump’s friend.