The timing might have come as a surprise, but this is no political shock. The real shock would have been if Theresa May hadn’t called an early election at some point during this Parliament.

The Prime Minister’s majority in the Commons is wafer-thin, she is about to negotiate the UK’s most significant policy change for decades without a direct mandate on the detail of that change, and the economy is still in relatively good shape, for now. Perhaps above all, however, the Labour opposition is about as effective as a chocolate fireguard.

Holding the election makes a lot of strategic sense. It will likely strengthen the prime minister’s parliamentary position and give her a freer hand during the negotiations with the European Union. With Labour in perpetual turmoil, she will make every effort to distinguish herself from Jeremy Corbyn.

“Let us remove the risk of uncertainty and instability, and continue to give the country the strong and stable leadership it demands.”

The strategic move comes with a number of precarious blind spots. If this election is really designed to “remove the risk of uncertainty and instability” and to deliver “strong and stable leadership,” she cannot be referring to the whole country.

In England and Wales, Brexit will be the issue. Theresa May has told us that “Brexit means Brexit.” This campaign gives her a chance to make the case for her version of Brexit. Labour will find itself even more divided than the Conservatives, while the Liberal Democrats stand to make some (limited) gains.

In Scotland, independence will be the issue. First Minister Nicola Sturgeon has described the PM’s decision to call for an election as a “huge political miscalculation.” She will use the election to portray Theresa May’s vision for Brexit as harmful to Scottish interests and, undoubtedly, seek a new mandate for a second independence referendum.

This is likely to have featured in Mrs May’s calculations, but she must feel that it’s a risk worth taking. There has been no major surge in support for independence so far, and the Conservatives could well pick up a number of seats from the SNP under Ruth Davidson’s energetic leadership.

It is Northern Ireland that appears to have played the smallest factor in the PM’s calculations.

Here, the division between unionism and nationalism will, yet again, dominate. Sinn Féin will seek to build on its recent momentum by re-mobilising voters who turned out in last month’s Assembly election. Meanwhile, the DUP will use every opportunity to remind unionist voters of Sinn Féin’s recent success and repeat its calls for unionist unity.

We have already seen the signs. Over Easter Gerry Adams made clear his desire for another Assembly election; Arlene Foster described the upcoming general election as “an opportunity to vote for the Union.” It will be a bitter, brutal campaign.

Last month, senior Conservatives threatened war with Spain over the post-Brexit status of Gibraltar. The following week, as a then deadline loomed for parties here to form an Executive, Mrs May went on holiday. On her tour of the UK before triggering Article 50, she visited Wales and Scotland – before returning to Wales on holiday. In Northern Ireland, she was a no-show.

It would be tempting, therefore, to conclude that Northern Ireland played almost no role in Mrs May’s decision. SDLP Leader Colum Eastwood didn’t hide his exasperation. “It tells you all you need to know about Theresa May,” he said, “that she would call a snap Westminster election in the middle of intense efforts to restore power-sharing government here.”

An election in June will likely have a disastrous effect on inter-party talks. If any chance of a deal was already slim, it just got even slimmer.

Perhaps, however, Downing Street had already concluded that a deal between the DUP and Sinn Féin was highly remote. Sinn Féin has made little secret of its appetite for a second election, while the DUP’s Sir Jeffrey Donaldson said only yesterday that Northern Ireland was “headed for direct rule” at the current rate.

In a bizarre, and chaotic way, will a general election help to keep both parties happy?

It certainly lets them off the hook. Instead of governing, or negotiating how to govern together, they appear undaunted by the prospect of Northern Ireland’s fourth election in two years. Even if another Assembly election is held on the same day, a ‘zombie government’ could be in place until at least September – and an extended power vacuum comes at a cost.

If Northern Ireland’s two largest parties genuinely wanted to govern together (as they are constitutionally required to do), they would have reacted very differently to news of another election. An election is fundamentally about competition, not cooperation.

Northern Ireland probably played very little role in Mrs May’s decision to call for an election. A successful outcome to negotiations here may well have been sacrificed to the bigger picture of Brexit negotiations. Yet, in reality, the decision might fit very well with the strategic calculations of our largest parties.

Westminster politics may get greater certainty, but Stormont looks as precarious as ever.