Power-sharing in Northern Ireland has been one of the great political achievements of recent times.  For all its faults, it has ensured a consistent (though often shaky) settlement which has maintained the balance of power between both nationalist and unionist communities, and ensured that both sides continue to have their voices heard at Stormont.

But with the Democratic Unionist Party now holding the upper hand in a deal to prop up a bloodied Conservative Party clinging on to power, any return to a legitimate form of power-sharing is in peril.

As part of the 1998 Good Friday Agreement, to ensure the balance of power between nationalists and unionists the UK Government is to take on the responsibility of “honest broker”, a role which falls predominantly on the Secretary of State for Northern Ireland, James Brokenshire.

To play devil’s advocate, it is likely that had Jeremy Corbyn found himself as Prime Minister after last week’s election his premiership would have presented major difficulties in ensuring that the British Government plays the part of honest broker.

Mr Corbyn’s well-documented and much maligned history of support for the republican movement during the Troubles, often at the expense of furthering peace in the region, would likely have led to outcry from unionist community.

But the political reality means that the Conservatives rely on agreeing a deal with the DUP to stay in government, a party whose own history has been intricately connected with loyalist sectarianism.

Should the DUP agree to a “confidence and supply” arrangement with the Tories they will effectively position themselves so close to the UK government that it is hard to see how the devolved assembly at Stormont can be legitimately restored.

Fundamentally, the DUP will be the biggest winners, by a large margin. Despite an outcry across the rest of the UK from those becoming familiar with the party’s political positioning, in reality it would be surprising to see them simply adhere to demands of, say, Orange Order lodges to reinstate banned marches or bonfires.

Neither will they push their controversial social agenda on to the rest of Britain when much of this can be made law in Northern Ireland through the Assembly. Indeed, when it comes to issues like abortion, much of it already is law.

In return for a deal at Westminster, DUP leader Arlene Foster will be seeking bang for her buck. From this writer’s perspective, top of the list may be an assurance from the UK government to protect the Fresh Start Agreement (which provides over £500 million of government money to tackle the underlying causes of sectarianism), and to ensure greater investment more generally in the region.

The outcome will be more electoral influence for the DUP in Northern Ireland, and the entrenchment of Mrs Foster’s position as leader of her party.

Sinn Fein themselves are now presented with greater obstacles to the return of a peaceful power-sharing deal.

In March this year, an election was held in Northern Ireland following the resignation of Martin McGuinness as Deputy First Minister in protest against, among several other DUP-related issues, Arlene Foster’s mismanagement of the botched Renewable Heat Incentive (RHI) scheme.

Prior to the general election, Sinn Féin made it clear that they would not re-enter any power-sharing arrangement for as long as Mrs Foster remained First Minister. But now that the DUP are at the heart of the UK government, during power-sharing negotiations it is not hard to imagine the difficulties, both politically and in principle, which Sinn Féin would have in reaching a deal with their invigorated and empowered rivals.

Sinn Féin’s tradition of abstentionism means that the Conservative government will find it easier to survive. It also means that the cause of Irish nationalism in Westminster is not only dealt a blow by the heightened influence of the DUP, but completely absent following the defeat of Northern Ireland’s more moderate Social Democratic and Labour Party’s three MPs.

With the DUP in ascendancy in Parliament, and with Arlene Foster’s position strengthened, a legitimate return to power-sharing will be a bitter pill for Sinn Féin to swallow. Yet there would be little to stop the DUP from accusing their opponents of wrecking the chances of power-sharing.

The history of the DUP has proven them to be shrewd political negotiators, who along with Sinn Féin have navigated social and often sectarian divides to ensure a functioning governing body at Stormont; they will be willing and able to make this coalition work.

But influence comes at a high price. In Northern Ireland peace is still precious, achieved in large part through a system of cooperation at Stormont that is enshrined in the Good Friday Agreement.

Sectarianism is an old wound that has not yet fully closed, and the DUP risk pulling it wide open. The successes of the Northern Ireland peace process, and the healing that it is bringing for so many communities, could unravel before our eyes.